Prosciutto (Taranto). After the direct com- parison of plate VI11 of one paratype of L. bedullii with plate VI11 of the holotype of. Lepidopleuw (Leptochiton) ...
Giomle di Geologia, ser. 34 vol. 60, 1998, pp. 235-252, Bologna
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Chitons (Mollusca, Polyplacophora) collected during cruise CS96 in the Strait of Sicily l
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Bruno Dellilngelo - Via Mtrgelle,~e660. I-591W Prato. Claudio Lombardi - Via Marreorri 9. 1-40062 Molinella (Bologna). Marco Taviani - Isriruro di Geologia Manna. C.N.R.. Via Gokrri 101, 1- 40129 Bologna.
BRUNO DELL'ANGELO, CLAUDIO LOMBARDI and MARCOTAVIANI l l
Summary
i
As many as 17 species of chitons (Mollusca, Polyplacophora) have been collected during cruise CS96 in the Strait of Sicily. Most material is represented by loose plates found within coarse-grained skeletal sediments which typically drape starved areas of banks and shoals down to cn. 110 m of depth. While most material pertains to Recent assemblages, two subfossil plates of Hanleya nngeifar are considered as probably belonging to glacial Pleistocene deep-sea coral assemblages. The high number of chitons collected clearly reflects the existence of many different hard-bottom habitats in the study-area.
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Key words: Polyplacophora, Mollusca, Quaiernary. Siraii o1 Sicily
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Introduction
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Chitons are primitive shelled benthic molluscs belonging to the class Polyplacophora, known since the Early Paleozoic and today represented by more than 800 species. Members of this class are exclusively marine and distributed from supratidal to abyssal depths, typically associated to hard substrata (e.g., Squires and Goedert, 1995). Modern chitons secrete a Sr-rich aragonitic shell (Milliman, 1974) consisting of eight plates kept together by a chitinous girdle that gets easily loose post-mortem because of the disintegration of binding non-mineralized tissues. Thus, loose chiton plates may contribute in forming biogenic skeletal sediments, although they are quantitatively scarce and only occasionally recorded in the literature as a minor constituent (Paleozoic: Lang et al., 1982; Recent: Wilson, 1979, among others). Possible exceptions are skeletal assemblages enriched in chiton-plates known from early Pliocene and early Pleistocene shallow-water deposits of Tuscany (Laghi, 1984; Dell'Angelo and Forli, 1995). Living individuals and loose plates of chitons have been found in many CS96 stations
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Scientific results of Cruise CS96 in the Strait of Sicily.
(Tab. 1) and the present contribution reports upon their taxonomic, ecologic and paleobiogeographic aspects.
Taxonomy We have identified 17 taxa at species level (Tab. 2). With only one exception (Hanleya nagelfar, probably a glacial Pleistocene fossil), al1 taxa belong to species typical of the Recent Mediterranean fauna. Class POLYPLACOPHORA Gray 1821 Order NEOLORICATA Bergenhayn 1955 Suborder LEPIDOPLEURINA Thiele 1910 Superfamily LEPIDOPLEUROIDEA Dell'Angelo and Palazzi 1991 Family LEPIDOPLEURIDAE Pilsbry 1892 Genus Lepidopleurus Risso 1826 Subgenus Lepidopleurus S.S. Lepidopleurus (Lepidopleurus) cajetanus (POLI,1791) P1. 1, Fig. 8
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E. Dell'Angelo, C. Lomùardi and M. Taviuni
Tab.
Chitons in Strait of Sicily
Tab. 1 - Location and characteristics of cruise CS96 stations mentioned in the text.
CRUISE CS 96 STATION
LATITUDE N
LONGTTUDE E
DEPTH (m)
22
37" 37" 37" 36" 36" 36" 36" 36" 37" 37" 37" 37" 37" 37" 37" 37" 37" 38" 36" 37" 37" 37" 37" 37" 37" 37" 37" 37" 37" 37" 37" 37"
12" 12" 11" 13" 13" 13" 13" 13" 12" 12" 12" 12" 12" 12" 12" 12" 12" 12" 11" 10" 1O" 1O" 10" 10" 10" 1O" 10" 10" 11" 11" 10" 11"
61 62 21 7 328 704 327 176 109 110 135 345 225 119 62 61 51 37 113 44 71 113 142 108 97 91 300 70 78 1 O1 38 45 63
30 32 36 37 5O 54 58 71 84 85 86 88 93 254 277 282 283 284 285 288 291 292 295 296 297 298
28' 28' 31 ' 52' 51' 51 ' 51' 49' 11' 10' 06' 07' 03' 52' 51' 51' 54' 14' 50' 48' 53' 53' 53' 52' 51' 51' 53' 54' 53' 54' 54' 54'
44" 58" 30" 33" 51" 49" 26" 55" 46" 46" 52" 59" 31" 00" 59" 55" 14" 07" 34" 05" 06" 39" 22" 20" 59" 56" 14" 14" 19" 12" 27" 28"
18' 17' 43' 06' 06' 07' 06' 04' 54' 46' 41' 42' 32' 17' 18' 18' 18' 32' 55' 53' 49' 48' 49' 49' 47' 53' 57' 58' 01' 01' 59' 02'
Selected references: 1791 Chiton cajetanus Poli, p.10, P1.4, Figs.1-2 1971 Lepidopleunts cajetanus Poli - Sabelli and Spada, p. 1, Figs.1-17
13" 27" 47" 12" 13" 06" 29" 21" 47" 04" 54" 39" 04" 56" 05" 17" 56" 49" 50" 18" 43" 39" 00" 30" 32" 33" 32" 13" 13" 52" 57" 04"
REMARKS ROCK DREDGE GRAB
ROCK DREDGE ROCK DREDGE GRAB GRAB GRAB
ROCK DREDGE GRAB GFlPB GRAB GRAB GRAB GRAB GRAB GRAB
ROCK DREDGE GRAB GRAB GRAB GRAB GRAB GFlPB GRAB GRAB GRAB GRAB
1985 Lepidopleum cajetanus Poli - Gaglini, p.1, P1.2, Fig.1; Pl. 8, Fig. 3 1985a Lepìdopleurus cajetanus Poli - Kaas and Van Belle, p.32, Fig.12 1989 Lepidopleurus (Lepìdopleurus) cajetanus
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Chitons in Straif o/ Sicily
(Poli) - Dell'Angelo and Palazzi, p.45, PI. 12 (cum,syn.) 1990 Lepidopleum cajetanus (Poli) - Mifsud et al., p.53, Fig.1 Material: st. 84 (Favignana isl., Secca del Toro, -62 m, grab), 1 plate. Remarks: L. cajetanus is the commonest Mediterranean Lepidopleurus. Differently from fully-grown adults, juveniles of this species may show some morphological variability. Our only plate (posterior) still mantains some juvenile features, including the lack of a fully developed chiselled sculpture, the presence of pronounced tubercle rows, and the anterior location of the mucro (Laghi, 1977). Ecology: L. cajetanus is a shallow water species distributed between 0.5 - 40 m (normally 1-5 m) under rocks and shells. Distribution: Eastern Atlantic ocean, from Brittany to Morocco and Canary Islands, Mediterranean sea. Subgenus Leptochiton Gray 1847
few loose plates collected at Laghi Alimini (Lecce), Capraia isl. (Leghorn) and Punta Prosciutto (Taranto). After the direct comparison of plate VI11 of one paratype of L. bedullii with plate VI11 of the holotype of Lepidopleuw (Leptochiton) boettgeri Sulc, 1934, from the Miocene of Kostej, Romania, Dell'Angelo and Palazzi (1989) have proposed the synonymy of this Mediterranean species with the Miocene taxon. However, this synonymy has been refused by Kaas and Van Belle (1994), based on morphological and biogeographic arguments. Ecology: the ecologica1 requirements of L. bedullii are virtually unknown. The few findings reported so far are generically related to shallow water depths, associated to Posidonia oceanica meadows and coralligenous habitats. Distribution: Apulian coasts (Laghi Alimini, Porto Cesareo, Punta Prosciutto), Tuscany (Capraia, Elba), Sicily (Vendicari), Malta (Mifsud et al., 1990), Tunisia (Kaas, 1989; Kaas and Van Belle, 1987), Turkey (Kaas and Van Belle, 1987), Greece (Strack, 1988; Kaas and Van Belle, 1987) and Cyprus (Cecalupo and Quadri, 1996).
Lepidopleurus (Leptochiton) bedullii (DELL'ANGELO and PALAZZI, 1986), P1. 1, Fig. 5
Lepidopieums (Leptochiton) (SOWERBY, 1840) PI. 1, Fig. 1
cancellatus
Selected references: 1986 Leptochiton (L.) bedullii Dell'Angelo and Palazzi, p. 7, Figs. 17-18, 23-24, 27-31, 49-50, 58-62 1987 Leptochiton (L.) bedullii Dell'Angelo and Palazzi - Kaas and Van Belle, p. 12, Fig. 4 1989 Lepidopleum (Leptochiton) boettgeri Sulc - Del17Angeloand Palazzi, p. 72, PI. 20, 22, Fig.5 (cum syn.) 1990 Leptochiton bedullii Del17Angelo and Palazzi - Mifsud et al., p. 54 1994 Leptochiton (L.) bedullii Dell'Angelo and Palazzi - Kaas and Van Belle, p. 9 Material: st. 88 (Favignana isl.,-36 m, grab), 1 plate.
Selected references: 1840 Chiton cancellatus Sowerby, Fig. 104, 104a-b, 105 1985a Leptochiton (L.) cancellatus (Sowerby) - Kaas and Van Belle, p.43, Fig. 16 1985 Lepidopleum cancellatus (Sowerby) Gaglini, p.2, PI. 2, Fig. 4 1986 Leptochiton (L.) cancellahrs (Sowerby)-~ell'~ngelo and Palazzi, p. 10, ~ i ~6-8, s . 41, 51, 65, 67, 69 1987 Leptochiton (L.) cancellatus (Sowerby) - Cesari, p.6, P1. 1, Fig. 1-7 1989 Lepidopleuw (Leptochiton) cancellatus (Sowerby) - Dell'Angelo and Palazzi, p. 58, Pls.6-7 (cum syn.) 1990 Leptochiton cancellatus (Sowerby) Mifsud, p. 54
Remarks: we have recovered only one, somewhat worn plate. This elusive taxon has been described by De117Angeloand Palazzi (1986) after three living individuals and a
Material: st. 36 (Strait of Sicily, -3271176 m, rock dredge), 1 plate; st. 58 (-3451225 m, rock dredge), 3 plates; st. 88 (Favignana isl., -36 m, grab), 44 plates; st. 93 (Scuso bank,
Chitons in SiraL of Sicily
-113 m, grab), 4 plates; st. 277 (Skerki bank, -71 m, grab), 1 spm. (length 3 mm). Remarks: most small-sized Atlantic and Mediterranean Leptochiton collected between 30-100 m of depth have been often acritically referred to the present species, although some are attributable to closer taxa, ie., Lepidopleurus scabndus (Jeffreys, 1880), L.sarsi Kaas, 1981 and L.cimicoides (Monterosato, 1879). Leptochiton cancellatus is well defined by (i) the sculpture of the centra1 areas of the posterior and intermediate plates, formed by a network of about 60 closespaced longitudinal striae of coalescent granules (Dell'Angelo and Palazzi, 1986: Fig. 41), (ii) the characteristic and ubiquitous trellis ornamentation of the plates, and (iii) the regularly rounded outline of the intermediate plates. Ecology: L.cancellatus has a wide bathymetric range, being distributed from extreme low tide (Brittany: Fischer, 1978) to 920 m, although it is more frequent between 10 and 100 m (Kaas and Van Belle, 1985a). Off the Italian coasts, there are records of this taxon from mid-shelf shelly hash, deep-sea coral assemblages and bathyal muds (Biondi and Di Paco, 1996). Distribution: L.cancellatus is confirmed from the Atlantic coasts of the British Isles, France, Spain and Portugal; in the Mediterranean it has been sporadically recorded from the Tyrrhenian sea (Giannutri isl., offshore Naples), Adriatic sea (lagoon of Venice) and Ionian sea (Amendolara bank), Strait of Sicily (Malta) and Aegean sea (Greece).
1985 Lepidopleurus cancellatus Auct. (not Sowerby) - Gaglini, P1. 7, Fig. 6 1987 Leptochiton (Leptochiton) sp.nov.? Cesari, p. 10, P!. 7, Figs. 1-5; P1. 8, Figs. 1-5; PI. 11, Figs. 1-3 1987 Leptochiton (L.) cimicozdes (Monterosato) - Dell'Angelo and Palazzi, p. 97, Figs. 1-15 (cum yn.) 1989 Lepidopleurus (Leptochiton) cimicoides (Monterosato) - Del17Angeloand Palazzi, p. 64, Pls. 14-15 (cum yn.) 1990 Leptochiton (L.) cimicoides (Monterosato) - Kaas and Van Belle, p. 7, Fig. 1 Material: st. 71 (Graham bank, -119 m, grab), 1 plate; st. 285 (Skerki bank, -91 m, grab), 1 specimen found alive on a rhodolith (length 2 mm). Remarks: this small and uncommon spec i e ~has been often confused with other minute Lepidopleurus, especially with L.cance1latus, as already discussed above. This taxon has been recently reviewed by Dell'Angelo and Palazzi (1987) who have also synonymized the species under scrutiny with Lepidopleurus intennedius Salvini-Plawen, 1968. Leptochiton sp.nov.? described and figured by Cesari (1987) based on two individuals collected from the Adriatic sea between 70110 m of depth, may well belong to this taxon. Ecology: there are no detailed informations about the ecologic requirements of this shallow water taxon.
Lepidopleurus (Leptochiton) cimicoides (MONTEROSATO, 1879) P1. 1, Fig. 9, P1. 2, Figs. 3-4
Distribution: Lepidopleurus cimicoides has been uncommonly recorded from the coasts of Sicily (Palermo, Siracusa, Porto Palo), Tuscany (Capraia isl.), Latium (Tor Paterno shoal), Croatia (Dalmatia) and Provence. It is also known in the Eastern Atlantic (West Sahara).
Selected references: 1879 Chiton cimicoides Monterosato, p. 23
Lepidopleurus (Leptochiton) (KAASand VANBELLE,1985)
geronensis
PI. l - 1, Lepidoplem cancellatus ((396-277) length 3 mm; 2, Lepidopleurus afrcanus ((396-254) length 23.5 mm; 3, Lepidopleurus africanus (CS96-93), intermediate valve, width 2.4 mm; 4, Lepidopleurus afncanus ((396-93) valve VIII, lateral view, width 2.5 mm; 5, Lepidopleum bedullii (CS96-88), valve VIII, width 2 mm; 6, Lepidopleum ajkcanus (CS96-22), length 8 mm; 7, Lepidopleum africanus (CS96-93), valve VIII, width 2.5 mm; 8, Lepidopleurus cajetanus ((396-84), valve VIII, width 2 mm; 9, Lepidopleurus cimicoides (CS96-285), length 2 mm; 10, Hanleya nagelfar (CS96-32), valve VIII, width 8.2 mm.
B. Dell'Angelo, C. Lombardi and M. Taviani
Selected references: 1985a Leptochiton (L.) geronensk Kaas and Van Belle, p. 67, Fig. 28 1985 Leptochiton ~eronensisKaas and Van Belle - ella s ella and Dell'Angelo, p.309, Fig. 1 1930 Leptochiton geronensis (Kaas and Van Belle) - Mifsud et al., p. 54, Fig. 2
1989 Lepidopleurus (Parachiton) afncanus Nierstrasz - Dell'Angelo and Palazzi, p. 80, Pls. 23-24 (cum syn.) 1990 Leptochiton (Parachiton) afncanus (Nierstrasz) - Bedulli, Dell'Angelo and Panetta, p. 31 1990 Leptochiton afncanus Nierstrasz - Mifsud et al., p. 54, Fig. 12
Material: st. 30 (-217 m, grab), 1 spm.
Material: st. 22 (-62 m, rock dredge), 1 spm. (length 8 mm); st. 50 (Terribile bank, -110 m, grab), 1 plate; st. 93 (Scuso bank, -113 m, grab), 18 plates; st. 254 (Pantelleria isl., -44 m, grab), 1 spm. (length 23.5 mm); st. 282 (Skerki bank, -1131141 m, dredge), 5 plates; st. 283 (Skerki bank, -107 m, grab): 2 plates; st. 285 (Skerki bank, -91 m, grab), 1 plate; st. 291 (Skerki bank, -70 m, grab), 1 plate; st. 292 (Skerki bank, -78 m, grab), 3 plates; st. 295 (Skerki bank, -101 m, grab), 2 plates.
Remarks: we have found one single, small living individua1 of this rare polyplacophoran. This species has been established from two specimens collected by fishermens off Gerona (Spain) between 200-250 m. Ecology: L. geronensis is a deep-water species distributed below 100 m of depth and found in association with ahermatypic corals (Spain) and coralligenous habitats (Tuscan archipel). Distribution: so far reported only from the Mediterranean basin, viz. Gerona, Formiche di Grosseto (Tuscan archipel), and Malta. Subgenus Parachiton Thiele 1909 Lepidopleurus (Parachiton) africanus Nierstrasz 1906, P1. 1, Figs. 2-4, 6-7
Selected references: 1906 Lepidopleurus afncanus Nierstrasz, p.155, PI. 3, Figs. 1-9 1981 Lepidopleurus (Parachiton) afncanus Nierstrasz - Laghi, Russo and Dell'Angelo, p. 1, Pl. 1, Figs. 3-9 1985a Leptochiton (Parachiton) afncanus (Nierstrasz) - Kaas and Van Belle, p. 163, Fig. 75 1987 Leptochiton (Parachiton) afncanus (Nierstrasz) - Cesari, p. 12, P1. 9, Figs. 1-6; P1. 10, Figs.1-5
Remarks: L. afrcanus is a rare species, originally described from a single specimen found in Algerian waters. No other records have been reported for about 70 years until a second specimen was found at Gallipoli (Apulia), followed by sporadic findings in the Tyrrhenian and Ionian seas (Bedulli et al., 1990). We have found two living individuals plus a number of loose plates, the latter mostly within the biogenic fraction of the coarse sediment carpeting the Skerki bank below 70 m. The living specimen dredged off Pantelleria isl. is exceptional since attaining the largest known size for this taxon which normally averages 7-10 mm of length, and because it shows an unusual purplish, redspotted colour. Ecology: this taxon seems typically associated to rhodalgal biogenic sediments, between 25-150 m. Our records confirm this interpretation since our two individuals have been found attached on a dead shell of Pecten jacobaeus and on a living rhodolith. Furt-
Pl. 2 - 1 , Hanleya hanleyi (CS96-84), intermediate valve, width 2.5 mm; 2, Hanleya hanleyi (CS96-93), valve VIII, width 1.5 mm; 3, Lepidopleum cimicoides ((396-71), valve VIII, width 1.5 mm; 4, Lepidopleum cimicoides (CS9671). valve VIII, detail of sculpture (230 x); 5, Callochiton calcatus (CS96-88), intermediate valve, width 1.5 mm; 6, Ischnochiton vanbellei (CS96-283), intermediate valve, width 3 mm; 7, Callochiton calcatus (CS96-88). intermediate valve, anterior view, width 1.5 mm; 8, Ischnochiton vanbellei (CS96-283), valve VIII, width 3 mm.
Chirons in Srrair of Sici
B. Dell'Angelo, C. Lombardi and M. Taviani
hermore, loose plates are not uncommon within calcareous-algal-rich biogenic sediment.
Northamerican coasts; it is rare in the Mediterranean. Hanleya nagelfar (LovÉN, 1864) P1. 1, Fig.10
Distribution: although rare or localized, this species has a wide biogeographic distribution in the Mediterranean basin, from Spain to Greece. Family HANLEYIDAE Bergenhayn 1955 Genus Hanleya Gray 1857 Hanleya hanleyi (BEANIN THORPE, 1844) p1.2, fig.1- 2 Selected references: 1844 Chiton hanleyi Bean in Thorpe, p. 263, Fig. 57 1972 Hanleya hanleyi (Bean) - Sabelli, p. 97, Figs. 1-6 1974 Hanleya hanleyi (Bean) - Sabelli, p. 1, Fig.1-13 1985a Hanleya hanleyi (Bean in Thorpe) Kaas and Van Belle, p.193, Fig. 91 1985 Hanleya hanleyi (Bean in Thorpe) - Gaglini, P1. 4, Fig. 2 (cum syn.) 1990 Hanleya hanleyi (Bean in Thorpe) Mifsud et al., p.54 Material: st. 84 (Favignana isl., Secca del Toro, -62 m, grab), 8 plates; st. 93 (Scuso bank, -113 m, grab), 11 plates; st. 295 (Skerki bank, -101m, grab), 1 plate. Remarks: we have found only loose plates of this uncommon, relatively deep-sea taxon. Ecology: this species is found between 50 to 550 m (normally around 100 m) attached to dead shells and pebbles; also reported from deep-sea coral assemblages (Biondi and Di Paco, 1996). Distribution: Hanleya hanleyi is widely distributed in the Atlantic ocean from the Barents sea to Canary islands, and off the
Selected references: 1846 Chiton nagelfar Lovén, p. 158 1985a Hanleya nagelfar (Lovén) - Kaas and Van Belle, p. 196, Fig. 92 1991 Hanleya nagelfar Lovén - Warèn and Kiitgaard, p. 51, Fig. 1- 7 1995 Hanleya nagelfar (Lovén) - Bellomo and Sabelli, p. 201, Fig. 1 Material: st. 32 (-3281704 m, rock dredge), 2 plates, 1 intermediate (10 mm) and 1 posterior (8.2 mm). Remarks: the finding of H. nagelfar in the study-area is quite significant. In fact, the two plates recovered from the Strait of Sicily, although well preserved, are likely sourced from glacial Pleistocene deep-sea coral deposits, whose presence has been documented in the same station (Maniscalco and Taviani, this volume). This taxon has been recently recorded as a «borea1 guest» from the lower Pleistocene of southern Italy (Contrada Case Alte, near Reggio Calabria: Bellomo and Sabelli, 1995). It is possible that the taxon is now extinct in the Mediterranean basin. Ecology: H. nagelfar is a rather large (up to 70 mm) species, associated to Choristid sponges belonging to Geodia, Isops, Snyphmus and Thenea often within deep-sea coral frames. it has been mostly recorded from 100-1000 m, with a few records as shallow as 55 m (Warèn and Kiitgaard, 1991). Distribution: H. nagelfar is widely distributed in the eastern Atlantic ocean (Greenland, Norway, Iceland, Faroes, Portugal) although it is only seldom recorded because of its peculiar habitat (Warèn and Klitgaard, 1991).
PI. 3 - 1, Callochiton septemvalvis (CS96-296), length 2.4 mm; 2, Ischnochiton rissoi (CS96-93), valve VIII, width 2.8 mm; 3, Chiton corallinus (CS96-292) valve VIII, width 4.5 mm; 4, Lepidochitona monterosatoi (CS96-88), valve I, width 1.8 mm; 5, Callochiton septemvalvis (CS96-292), valve VIII, width 2.8 mm; 6, Chiton comllinus (CS96-292), intermediate valve, width 4.7 mm; 7, Lepidochitona monterosatoi (CS96-88), intermediate valve, width 2.4 mm; 8, Acanthochitona fascicularis (CS96-93), intermediate valve, width 1.3 mm; 9, Acanthochitona fascicularis (CS96-88). valve VIII, width 1.3 mm.
Chitons in Stmit of Sicily
E. Dell'Angelo, C. Lombardi and M. Taviani
Suborder ISCHNOCHITONINA Bergenhayn 1930 Family ISCHNOCHITONIDAE Dall 1889 Subfamily ISCHNOCHITONINAE Dall 1889 Genus Ischnochiton Gray 1847 Subgenus Ischnochiton s.str.
Subgenus Stenosemus Middendorff 1847 Ischnochiton (Stenosemus) vanbellei KAAS 1985, P1. 2, Figs. 6, 8
Selected references: 1985 Ischnochiton (Stenosemus) vanbellei Kaas, p. 316, Figs. 55-68 Ischnochiton (Ischnochiton) rissoi (PAYRAU- 1990 Ischnochiton (Stenosemus) vanbellei Kaas - Kaas and Van Belle, p. 71, Fig. 29 DEAU,1826) Pl. 3, Fig. 2 1996 Ischnochiton (Stenosemus) vanbellei Selected references: Kaas - Biondi and Di Paco, p. 19 1826 Chiton rissoi Payraudeau, p. 87, Pl. 3, Figs. 4- 5 Material: st. 283 (Skerki bank, -107 m, 1908 Ischnochiton rissoi Payraudeau - Niergrab), 14 plates; st. 285 (Skerki bank, -91 m, strasz, p. 163, Figs. 10-14 grab), 1 plate; st. 295 (Skerki bank, -101 m, 1985 Ischnochiton rissoi (Payraudeau) - Gagrab), 3 plates. glini, P1. 5, Fig. 5; P1. 6, Figs. 3-4 (cum syn.) 1990 Ischnochiton (I.) rissoi (Payraudeau) Remarks: I.vanbellei is a rather rare speKaas and Van Belle, p. 78, Fig. 32 c i e ~previously recorded from a few locali1990 Ischnochiton rissoi (Payraudeau) - Mifties in association with deep-sea (white) cosud et al., p. 57, Figs. 8-9 rals. Our records are instead from rhodalgal 1993 Ischnochiton rissoi (Payraudeau) - Giosediments of the Skerki bank, at depths abovine and Dell'Angelo, p. 162 ve 100 m and deprived of deep-sea corals. Material: st. 84 (Favignana isl., Secca del Toro, -62 m, grab), 6 plates; st. 88 (Favignana isl., -36m, grab), 2 plates; st. 93 (Scuso bank, -113 m, grab), 23 plates; st. 254 (Pantelleria isl. -44 m, grab), 1 spm.; st. 282 (Skerki bank, -113/141 m, dredge), 13 plates; st. 283 (Skerki bank, -107 m, grab), 6 plates; st. 284 (Skerki bank, -97 m, grab), 1 plate; st. 285 (Skerki bank, -91 m, grab), 1 plate; st. 288 (Skerki bank, -300 m, grab), 1 plate; st. 291 (Skerki bank, -70 m, grab), 4 plates; st. 292 (Skerki bank, -78 m, grab), 2 plates; st. 295 (Skerki bank, -101 m, grab), 5 plates; st. 296 (Skerki bank, -38 m, grab), 1 spm.; st. 297 (Skerki bank, -45 m, grab), 1 spm. Remarks: this species is rather abundant in our material. It is a common Mediterranean polyplacophoran normally inhabiting very shallow habitats. Our living-collected specimens show a sculpture more subdued than the typical form. Ecology: Ischnochiton rissoi normally lives between 1-5 m adhering to rocky surfaces, stones or dead shells; rarely, it is found in deeper waters, always on hard substrata. Distribution: it is a typical Mediterranen taxon; records from the Canary islands and the Azores need to be confirmed.
Ecology: this taxon is confirmed from the white-coral biocoenosis (with Lophelia pertusa), since living individuals from the Tuscan archipel have been consistently found attached to coral branches between 200-500 m of depth (Biondi and Di Paco, 1996). We ignore whether the coral was alive or subfossil; however, there are records from shallower depths (Tuscan archipel, «Secca delle Vedove» -160 m: Bogi et al., 1989), including the present one, pointing out that the ecologic range of this species is not restricted to coral assemblages. Distribution: Tuscan archipel, Strait of Sicily and Mauritania. Subfamily CALLOCHITONINAE Plate 1901 Genus Callochiton Gray 1847 Callochiton calcatus DELL'ANGELO and PALAZZI 1994, PI. 2, Figs. 5, 7 Selected references: 1994 Callochiton calcatus Dell'Angelo and Palazzi, p. 15, Figs. 1-12, 14-19, 20B 1995 Callochiton calcatus Del17Angelo and Palazzi - Basso, p. 364
l
,
Chirons in Srrair of Sicily
1997 Callochiton calcatus Del17Angelo and Palazzi - Dell'Angelo and Giusti, p. 53, Fig. 7 Material: st. 71 (Graham bank, -119 m, grab), 1 plate; st. 88 (Favignana isl., -36 m grab), 40 plates. Remarks: Callochiton calcatus is a recently described species that differs from the other known Mediterranean species (C. septemvalvis) principally by its small size (maximum length 5 mm), noticeable dorsal elevation, more raised lateral areas, and uniform colour patterns. Ecology: the species is found at depths between 30 and 100 m, and is probably linked with coralligenous and maerl habitats. A possible association of C. calcatus with the calcareous alga Lithothamnion valens Foslie 1909, is suggested by Basso (1995). Distribution: this rare taxon is at present only known for the Mediterranean basin, ranging from the Balearic isles to the Tyrrhenian coasts of Italy and Sicily. Callochiton septemvalvis (MONTAGU, 1803), P1. 3, Figs. 1, 5
Selected references: 1803 Chiton septemvalvis Montagu, p. 3 1985 Callochiton euplaeae (0.G.Costa) - Gaglini, P1. 9, Fig. 4; PI. 8, Figs. 5-6; P1. 9, Figs. 1-2 (cum syn. ) 1985b Callochiton septemvalvis (Montagu) Kaas and Van Belle, p. 11, Fig. 2 (cum syn.) 1990 Callochiton septemvalvis (Montagu) Mifsud et al., p. 56, Fig. 11 1993 Callochiton septemvalvis euplaeae (O.G. Costa) - Giovine and Dell'Angelo, p. 161 1994 Callochiton septemvalvis (Montagu) Dell'Angelo and Palazzi, p. 15, Figs. 13,20A Material: st. 37 (-109 m grab), 3 plates; st. 71 (Graham bank, -119 m, grab), 4 plates; st. 84 (Favignana isl., Secca del Toro, -62 m, grab), 17 plates; st. 85 (Favignana isl., Secca del Toro, -61 m, grab), 3 plates; st. 86 (Favignana isl., Secca del Toro, -51 m, grab), 1 plate; st.88 (Favignana isl., -36 m, grab), 23 plates; st. 93 (Scuso bank, -113 m, grab), 11 plates; st. 282 (Skerki bank, -1131141 m, dredge), 17 plates; st. 283 (Skerki bank, -107
m, grab), 14 plates; st. 284 (Skerki bank, -97 m, grab), 1 plate; st. 285 (Skerki bank, -91 m, grab), 11 plates; st. 291 (Skerki bank, -70 m, grab), 10 plates; st. 292 (Skerki bank, -78 m, grab), 11 plates; st. 295 (Skerki bank, -101 m, grab), 10 plates; st. 296 (Skerki bank; -38 m, grab), 2 spm.; st. 298 (Skerki bank, -64 m, grab), 3 plates. Remarks: this Mediterranean Callochiton has been confused until recent times with C. laevis (Montagu, 1803, not Pennant, 1777) and C. achatinus (Brown, 1823). Kaas (1978) has proposed to adopt the name C. septemvalvis (Montagu, 1803), and to separate subspecifically the typical Atlantic form, viz., C. septemvalvis septemvalvis, from the Mediterranean one, viz., C. septemvalvis euplaeae ( 0 . G. Costa, 1829); the latter is characterized by a smaller size and by the presence of 3-5 longitudinal grooves on both sides of the centra1 areas, which may or may not reach the front margins of the valves. Dell'Angelo and Palazzi (1994) suggested to adopt the taxon Callochiton septemvalvis (Montagu, 1803) to designate this species in its complex, also considering that Chiton euplaeae was clearly described by O. G. Costa (1829) as a species with a smooth surface, without any trace of scars. Nearly al1 collected plates show some longitudinal grooves on the pleural area. Ecology: C. septemvalvis lives from the upper subtidal zone down to a depth of 500 m, more frequently on corallinous algae. Distribution: the species is widely distributed in the Atlantic Ocean from Norway to the Canary islands, and in the Mediterranean. Subfamily LEPIDOCHITONINAE Iredale 1914 Genus Lepidochitona Gray 1821 Subgenus Lepidochitona s.str. Lepidochitona (L.) furtiva (MONTEROSATO, 1879)
Selected references: 1879 Chiton jùrtivus Monterosato, p. 19 1981 Lepidochitona (L.) jùrtiva (Di Monterosato) - Kaas and Van Belle, p. 34, Figs. 113-127
1985 Lepidochitona furtiva (Monterosato) Gaglini, P1. 9, Fig. 5; P1. 6, Figs. 5-6 1985b Lepidochitona (L.) furtiva (Monterosato) - Kaas and Van Belle, p. 91, Fig. 42 1987 Lepidochitona (L.) furtiva (Monterosato) - Kaas and Van Belle, p. 29, Fig. 13 1990 Lepldochitona furtiva (Monterosato) Mifsud et al., p. 57, Fig. 7 Material: st. 88 (Favignana isl., -36 m, grab), 12 plates. Remarks: L. furtiva was described by Monterosato (1879) upon some fifty specimens collected near Palermo between 20-30 m of depth. For more than a century this species was not recorded again unti1 some specimens where found attached to Posidonia oceanica rhizomes stranded on the beach of Cap d'Antibes (Kaas and Van Belle, 1981). More recently, additional specimens have been collected in the Pontian archipel (Gravina et al., 1992) but the taxon still remains one of the most elusive Mediterranean polyplacophorans. Ecology: little is known about its ecologic requirements but the species seems to be in some way associated to Posidonia oceanica meadows. Distribution: only known from the Mediterranean Sea, with sporadic records for Sicily (Palermo), Pontian archipel (Zannone isl.), France (Cap d'Antibes), Corsica (Calvi), Malta, Algeria (Orano), Tunisia (Djerba). Lepidochitona (L.) monterosatoi KAASand VANBELLE,1981, P!. 3, Figs. 4, 7 Selected references: 1981 Lepidochitona (L.) monterosatoi Kaas and Van Belle, p. 23, Figs. 57-72 1983 Lepidochitona monterosatoi (Kaas and Van Belle) - Biondi et al., p. 91, Figs. 7-8 1985 Lepidochitona monterosatoi Kaas and Van Belle - Gaglini, P!. 10, Figs. 3-4 1985b Lepidochitona (L.) monterosatoi Kaas and Van Belle - Kaas and Van Belle, p. 99, Fig. 46 1993 Lepidochitona cfr. monterosatoi Kaas and Van Belle - Giovine and Dell'Angelo, p. 169, P1. 1, Fig. 6 1993 Lepidochitona monterosatoi Kaas and Van Belle - Strack, p. 8, PI. 2, Fig. 9
Material: st. 88 (Favignana isl., -36 m, grab), 2 plates. Remarks: Lepidochitona monterosatoi is a small-sized species (up to 12 mm) not very frequent but easily distinguishable from the other Mediterranean Lepidochitona for its dorsal elevation, beaked apex of intermediate plates, peculiar disposition of granules over the pleural areas of intermediate plates, and presence of isolated and long curved spines on the girdle. Ecology: the species seems to be preferentially associated to calcareous algae between ca. 0.5140 m, from pre-coralligenous to coralligenous habitats, normally inside microcavities (Biondi et al., 1983). Distribution: this Mediterranean species has been sporadically recorded from the Tuscan Archipel, Leghorn, Capraia isl., Sicily (Acitrezza), Sardinia, France (Cap d'Antibes, Toulon), Dalmatia (Murter), Turkey (Torbo), Cyprus, Greece, Tunisia, Spain. It has been also reported from the Red Sea (Dahlak archipel) by Strack (1993) but this anomalous record needs to be confirmed. Family CHITONIDAE Rafinesque 1815 Subfamily CHITONINAE Rafinesque 1815 Genus Chiton Linné 1758 Subgenus Rhyssoplax Thiele 1893 Chiton (Rhyssoplax) corallinus (R~sso, 1826), P1. 3, Figs. 3, 6 Selected references: 1826 Lepidopleurus corallinus Risso, p. 268 1974 Chiton corallinus (Risso) - Sabelli, p. 1, Figs. 1-13 1978 Chiton corallinus (Risso) -. Sabelli, p. 269, Figs. 5-6, 11-12, 19 1983 Chiton corallinus (Risso) - Biondi et al., p. 94 1985 Chiton corallinus (Risso) - Gaglini, PI. 14, Fig. 2; P1. 6, Figs. 1-2 (cum syn. ) 1990 Chiton corallinus (Risso) - Mifsud et al., p. 57, Fig. 6 Material: st. 37 (-109 m, grab), 22 plates; st. 54 (Graham bank, -135 m, grab), 3 plates; st. 84 (Favignana isl., Secca del Toro, -62 m, grab), 94 plates; st. 88 (Favignana isl., -36 m,
grab), 22 plates; st. 93 (Scuso bank, -113 m, grab), 19 plates; st. 282 (Skerki bank, -1131 141 m, dredge), 56 plates; st. 283 (Skerki bank, -107 m, grab), 113 plates; st. 284 (Skerki bank, -97 m, grab), 5 plates; st. 285 (Skerki bank, -91 m, grab), 18 plates; st. 288 (Skerki bank, -300 m, grab), 3 plates; st. 289 (Skerki bank, -113 m, grab), 2 plates; st. 291 (Skerki bank, -70 m, grab), 105 plates; st. 292 (Skerki bank, -78 m, grab): 52 plates; st. 295 (Skerki bank, -101 m, grab), 46 plates; st. 296 (Skerki bank, -38 m, grab), 4 spm.; st. 297 (Skerki bank, -45 m, grab), 1 spm.; st. 298 (Skerki bank, -64 m, grab), 4 plates. Remarks: this relatively uncommon chiton is the most represented polyplacophoran in CS96 biogenic sediments, with hundreds of loose plates; two specimens have been found alive on the Skerki bank. Ecology: C. corallinus is normally found between 15-100 m and more, generally associated to coralligenous habitats. Distribution: this species is widely distributed in the Mediterranean sea of which it is apparently endemic. The Red Sea record of C. corallinus by Leloup (1960) is to be referred to the Indo-Pacific taxon Chiton maldivenszi (E. A. Smith, 1903). Suborder ACANTHOCHITONINA Bergenhayn 1930 Familv ACANTHOCHITONIDAE Piisbw 1893 Subfamily ACANTHOCHITONINAE Pilsbry 1893 Genus Acanthochitona Gray 1821 Acanthochitona fascicularis (LINNÉ,1767), Pl. 3, Figs. 8, 9
Selected references: 1767 Chiton fascicularis Linné, n. 1106 1982 Acanthochitona communis (Risso) Biondi and Di Paco, p. 73, PI. 2 1985 Acanthochitona aenea (Risso) - Gaglini, pl. 17, Figs. 2-3; P1. 10, Figs. 3-4 (cum syn.) 1985a Acanthochitona fascicularis (Linné) Kaas, p. 585, Figs. 1-6 1990 Acanthochitona fascicularis (Linné) Mifsud et al., p. 60, Fig. 3 1993 Acanthochitona fascicularis (Linné) Giovine and Dell'Angelo, p. 165
Material: st. 71 (Graham bank, -119 m, grab), 7 plates; st.88 (Favignana isl., -36 m, grab), 20 plates; st. 93 (Scuso bank, -113 m, grab), 13 plates; st. 282 (Skerki bank, -113/ 141 m, dredge), 1 plate; st. 288 (Skerki bank, -300 m, grab), 1 plate; st.291 (Skerki bank, -70 m, grab), 15 plates; st. 292 (Skerki bank, -78 m grab), 1 plate; st. 298 (Skerki bank, -64 m, grab), 5 plates. Remarks: A. fascicularis is an exceedingly variable species and, accordingly, its synonymy is quite complicate (Kaas, 1985). We have found only loose plates of this common taxon. Ecology: A. fascicularis is a shallow-water species normally found beneath stones covered by seaweeds. Distribution: the taxon is widely distributed in the Atlantic ocean, from the English Channel to the Azores and Canary islands, and throughout the Mediterranean sea. Acanthochitona crinita (PENNANT, 1777)
Selected references: 1777 Chiton crinitus Pennant, p. 71, P1. 36, Fig. 1, A l 1983 Acanthochitona fascicularis (L.) - Biondi et al., p. 94, Fig. 6 1985 Acanthochitona fascicularis (L.) - Gaglini, PI. 16, Fig. 1; P1. 9, Figs. 3-6 1985a Acanthochitona crinita (Pennant) Kaas, p. 588, Figs. 7-50 1990 Acanthochitona crinita (Pennant) - Mifsud et al., p. 60, Fig. 1 1993 Acanthochitona crinita (Pennant)-Giovine and Dell'Angelo, p. 168 Material: st. 71 (Graham bank, -119 m, grab), 1 plate; st. 88 (Favignana isl., -36 m, grab), 4 plates. Remarks: this species is far less common than A. fascicularis from which it can be easily separated by differences in the length of the girdle spicules, ellipsoidal outline of intermediate plates and shape of the tegmentum's granules. Ecology: the species is distributed from the intertidal zone down to pre-coralligenous and coralligenous habitats.
B. DellAngelo, C. Lombardi and M. Taviani
Distribution: the taxon is distributed in the Atlantic ocean, from the Lofoten islands to Cape Vert archipel and throughout the Mediterranean sea.
Discussion The extensive bottom sampling carried out in the Strait of Sicily and offshore the western side of Sicily during cruise CS96, has led to the collection of 17 species belonging to the Class Polyplacophora. Only 7 species have been living-collected by us, among these two rare species, i.e., Lepidopleurus (Leptochiton) geronensis and Lepidopleurus afncanus (largest known specimen). Most materia1 is represented by loose plates found within the coarse fraction of biogenic sediments. The high number of species identified in our samples, approaching 70% of the present-day Mediterranean chiton fauna, reflects the variety of substrata tested during our campaign and the high incidence
of hard bottoms suitable for the settlement of polyplacophorans in the study area. Many of the «missing» Mediterranean taxa are shallow-water species whose chances to be living-collected or found as loose plates are understandably minimal. One species today typical of the NE Atl a n t i ~ocean (Hanleya nagelfar) is considered to be likely extinct in the Mediterranean sea and probably belonging to unburied glacial Pleistocene assemblages. Although chiton plates are never quantitatively abundant, they are nevertheless ubiquitous in most coarse-grained skeletal sediments typically draping starved areas of banks and shoals between 3-110 m of depth.
Acknowledgements We are indebted to Marco Oliverio, Amalia Pandolfo and Vittorio Garilli for their help in sorting chiton plates and to Alessandro Remia and Massimo Salmi for editing table and rnap.ihe tea has been critically reviewed by Sergio Raffi and an unknown referee. This is IGM scientific contribution n.m.
REFERENCES BARASH A. and DANIN Z., 1977. Polyplacophora (Mollusca) from the Eastern Mediterranean. J.de Conch., 11411-2, 1-28. BASSOD., 1995. Living calcareous algae by a paleontologica1 approach: the genus Lirhothamnion Heydrich nom.cons. from the soft bottoms of the Tyrrhenian Sea (Mediterranean). Riv. It. Paleont. Strat., 10113, 349-366. BEDULLID., DELL'ANGELO B. and PANETTAP., 1990. Osservazioni sull'ecologia di Leptochiton (Pamchiton) afncanus (Nierstrasz,l906). Atti I1 Congr. S. I. M., Lavori S.I.M., 23: 31-36. BELLOMO E. and SABELLI B., 1995. A new addition to the Mediterranean Pleistocene Borea1 Guests: Hanleya nagelfar (Lovén, 1864) (Mollusca, Polyplacophora) from Calabria (S. Italy). Boll. Soc. Paleont. It., 3412, 201- 204. BIONDI F. and DI PACOG., 1996. Emarginula chrlrriaensi Piani, 1985 vivente in Mediterraneo (Mar Ligure). La Conchiglia, 281278). 17-20. BIONDIF., DELL'ANGELO B., DI PACOG., PALAZZIS. and SERENA F., 1983. Notizie preliminari su una formazione coralligena infralitorale rinvenuta lungo le coste livornesi, con osservazioni particolari sui molluschi. Quad. Mus. St. Nat. Livorno, 4, 77-106. BOGIC., COPPINI M. and MARGELLI A., 1989. Contributo alla conoscenza della malacofauna dell'alto Tirreno (Aggiornamento). La Conchiglia, 211238-241, 25-29. CESARIP., 1987. Note sistematiche e geonemiche su alcune specie mediterranee del genere Leptochiton
Gray, 1847 (Polyplacophora, Leptochitonidae). Lavori Soc. Ven. Sc. Nat., 12, 3-34 DELLABELLAG. and DELL'ANGELO B., 1985. Prima segnalazione di Leptochiton geronensis Kaas and Van Belle, 1985 lungo le coste italiane. Bollettino Malacologico, 21110-12, 309-310. DELL'ANGELO B. and FORLIM., 1995. I Polyplacophora del Pleistocene inferiore di Riparbella (Pisa), con elenco dei molluschi rinvenuti. Bollettino Malacologico, 3019-12 (1994), 221-252. DELL'ANGELO B. and PALAZZI S., 1986. Considerazioni sulla famiglia Leptochitonidae Dall, 1889 (Mollusca: Polyplacophora) con descrizione di due nuovi taxa. Bollettino Malacologico, 2211-4, 1-36. DELL'ANGELO B. and PALAZZIS., 1987. Considerazioni sulla famiglia Leptochitonidae Dall, 1889 (Mollusca: Polyplacophora). 11. Ridescrizione di Leprochiron cimicoides (Monterosato, 1879). Bollettino Malacologico, 2311-4, 95-105. DELL'ANGELO B. and PALAZZI S., 1989. Considerazioni sulla famiglia Leptochitonidae Dall, 1889 (Mollusca: Polyplacophora). 111. Le specie terziarie e quaternarie europee, con note sistematiche e filogenetiche. Atti I Giorn. Studi Malacol. CISMA, 19-140. DELL'ANGELO B. and PALAZZI S., 1991. Considerazioni sulla famiglia «Leptochitonidae» Dall, 1889 (Mollusca: Polyplacophora). IV. Aggiunte e correzioni. Bollettino Malacologico, 2711-4, 35-38. DELL'ANGELO B. and PALAZZI S., 1994. Callochiton calcaius n.sp. con note su Callochiton septemvalvk
!
I
/
se'an daora :on 110-
oni 5'3:
ura. ioni sa: i cioloioni 1sCa: mache.
I
I
(Montagu, 1803). La Conchiglia, 261273, 15-23. GAGLINI A., 1985. Classe Amphineura. In: F. Settepassi (1972). Atlante Malacologico. I Molluschi Marini viventi nel Mediterraneo. Vol. 111. TIP. INIVAG, Roma: 19 pp. GIOVINE F. and DELL'ANGELO B., 1993. Elenco dei molluschi rinvenuti nello Stretto di Messina. Polyplacophora. Atti I11 Congresso S.I.M., Parma 1990. Lavori S.I.M., 24,157-170. GRAVINA M.F., SMERIGLIO C. and ARDIZZONE G.D., 1992. Benthos di fondo mobile delle isole Pontine: 1. Molluschi. Atti XXII Congr. SIBM, Oebalia 17 suppl., 355-357. KAAS P., 1979. On a collection of Polyplacophora (Mollusca, Amphineura) from the Bay of Biscay. Bull. Mus. natn. Hist. nat. Paris, (4)A(1), 13-31. KAAs P., 1981. Scandinavian species of Leptochiron Gray, 1847 (Mollusca: Polyplacophora). Sarsia, 6613, 217-229. KAAs P., 1985. The genus Acanthochitona Gray, 1821 (Mollusca, Polyplacophora) in the north-eastern Atl a n t i ~Ocean and in the Mediterranean Sea, with designation of neotypes of A. fascicularis (L., 1767) and of A. crinira Pennant, 1777). Bull. Mus. natn. Hist. nat. Paris, (4)7(A3), 579-609. KAAs P. and KNUDSEN J., 1992. Lorentz Spengler's descriptions of chitons (Mollusca: Polyplacophora). Zool. Meded. Leiden, 66, 49-90. KAASP. and VAN BELLER.A., 1981. The genus Lepidochirona Gray, 1821 (Mollusca: Polyplacophora) in the Northeastern Atlantic Ocean, the Mediterranean Sea and the Black Sea. Zool. Verhand., 185, 3-43. KAAS P. and VAN BELLER.A., 1985a. Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 1. Order Neoloricata: Lepidopleurina. E. J. Brill/W. Backuys, Leiden. KAAs P. and VAN BELLER.A., 1985b. Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 2. Suborder Ischnochitonina, Ischnochitonidae: Schizoplacinae, Callochitoninae and Lepidochitoninae. E.J. BrillIW. Backhuys, Leiden. KAAs P. and VAN BELLER.A., 1987. Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 3. Suborder Ischnochitonina: Ischnochitonidae: Chaetopleurinae and Ischnochitoninae (pars). Additions to Vols 1 and 2. E.J. Brill/W. Backhuys, Leiden. KAAS P. and VAN BELLER.A., 1990. Monograph of Living Chitons (Mollusca: Polyplacophora). Vol. 4. Suborder Ischnochitonina: Ischnochitonidae: Ischnochitoninae (continued). Additions to Vols. 1, 2 and 3. E.J. Brill, Leiden. KAAs P. and VAN BELLER.A., 1994. Monograph of Livine Chitons (Mollusca: Poiv~iacoohora~. Vol. 5. Suboder lschnochitonina: lkhnochitonidae: Irhnochitoninae (concludedl, Callistoplacinae; Mopaliidae. ~ d d i t i ò n sto ~ 0 1 s :1-4. E.J. ~ r i l l Leiden. , ' LAGHIG.F., 1984. Sorprendente densità di Chiron saeniensis n.sD. in sabbie eialle ~liocenichedei dintorni di Serre d'i Rapolanol~iena).Boll. Mus. Reg. Sci. Nat. Torino, 212, 555-564.
LAGHIG.F., Russo F. and DELL'ANGELO B., 1981. Recenti ritrovamenti di Lepidopleurus (Parachiton) afncanus Nierstrasz, 1906 (Polyplacophora, Mollusca). Atti Soc. Nat. Mat. Modena, 111 (1980), 1-7. LANGV., MAREK J. and PEKI., 1982. A find of the species Rhombichiron larerodepressus (Bergenhayn, 1945) in the Culm of the Drahanska Vrchovina. Upland. Vestinik ustredninho usta vu geol., Praha, 5715, 299-302. LELOUP E., 1960. Amphineures du Golfe d'Aqaba et de la Peninsule Sinai. Bull. Sea Fish. Res. Sta. Haifa, 29, 29-55. MIFSUDC., CACHIA C. and SAMMUT P.M., 1990. Note sui ~oli~lacofori delle isole Maltesi. ~a Conchiglia, 221256, 52-61. MILLIMAN J.D., 1974. Marine Carbonates. SpringerVerlag, Berlin Heidelberg New York. MONTEROSATO M.T.A., 1879. Enumerazione e sinonimia delle Conchiglie mediterranee. Monografia dei Chitonidi del Mediterraneo. Giorn. Sci. Nat. Econ. Palermo, 14, 9-31. PILSBRY H.A., 1892194. Monograph of Polyplacophora. In: G. W. Tryon, Manual of Conchology. Acad. Nat. Sci., Philadelphia, 14, 1-128, pls. 1-30 (1892); i-xxxiv, 129-350, pls. 31-68 (1893); 15: 1-64, pls. 1-10 (1893); 65-133, pls. 11-17 (1894). SABELLI B., 1972. Sulla presenza e distribuzione di Hanleya hanleyi in Mediterraneo. Conchiglie, 817-8, 97-100. SABELLI B., 1973. On a Polyplacophora described by Monterosato. Malacologia, 14, 244-246. SABELLI B., 1974. Hanleya hanleyi (Bean, 1844). Schede Malacologiche del Mediterraneo, S. M. I. (87Ac01). SABELLI B., 1974. Chiton corallinus (Risso, 1826). Schede Malacologiche del Mediterraneo, S. M. I. (88Ea02). SABELLI B., 1978. I1 genere Chiton in Mediterraneo, osservazioni al mi&oscopio elettronico a scansione. Boll. Zool., 4513, 269-274. SABELLI B. and SPADAG., 1971. Lepidopleurus cajetanus (Poli, 1791). Schede Malacologiche del Mediterraneo, S. M. I. (87Aa01). SABELLI B. and TAVIANI M., 1979. I Polyplacophora del Pleistocene inferiore del T. Stirone (Preappennino Parmense, Italia). Boll. Soc. Paleont. It., 1812, 157161. SQUIRES R.L. and GOEDERT J.L., 1995. An extant spec i e ~of Leptochiton (Mollusca: Polyplacophora) in Eocene and Oligocene cold-seep limestones, Olyrnpic Peninsula, Washington. The Veliger, 3811, 47-53. STRACK H.L., 1988. The distribution of Chitons (Polyplacophora) in Greece. Apex, 314, 67-80. STRACK H.L., 1990. The distribution of Chitons (Polyplacophora) in Greece: addendum. Apex, 511-2, 1315. WARÈN A. and KLITGAARDA., 1991. Hanleya nagelfar, a sponge-feeding ecotype of H. hanleyi or a distinct species of chiton? Ophelia, 3411, 51-70. WILSONJ.B., 1979. Biogenic carbonate sediments on the Scottish continental shelf and on Rockall Bank. Marine Geology, 33, M85-M93.
