— 317 - 



dorsali antico leviter convexo, postico recto, declivi; umbonibus 

 post medium sitis, prominulis; ligamento prominente. Valvulae 

 crassae, albae, iiTegulariter concentrice striatae, plica distincta 

 ab umbonibus ad angulum posticum inferiorem instructae ; valv. 

 dextra magis convexa, major, sinistra plana, a dextra in margine 

 ventrali circumclusa. Cardine calloso, a forma typica divergente, 

 ossiculo destituto. — Long. 15-26, alt. 10—18, crass. 6—16 

 Mm. Becher. 



Thracia crassa Becber Jaii Mayeu p. 5 T. 6, F. 1. 

 Hab. ad insulam Jan Mayen. 



5. Tbracia praetenuis Pulteney. T. compressa, 

 elongato-ovata, leviter inaequivalvis, valvula dextra paulo majore, 

 extremitate antica late rotundata, postica paulo breviore et 

 multo angustiore, apice rotundato-truncato , margine ventrali 

 antice arcuato, postico subrecto et sat declivi, umbonibus paulo 

 pone medium sitis, subprominulis, postice crista arcuata definitis, 

 ligamento ext. minimo et inconspicuo. Valv. tenues, albae, 

 opacae, sublaeves, intus ad umbones crista brevi arcuata in- 

 structae, cardine processu magno cochleariformi , verticali pro 

 cartilagine praedito, ossiculo distincto falciformi. — Long. 27 

 Mm. Sars. 



Mya praetemus Pulteiiey Cat. Dorset p. 28 T. 4, F. 4. — (Cochl.) 

 Forbes et Hanley I p 235 T. 15, F. 4 - Sow. 111. Ind. T. 2, 

 F. 10. — (Tbr.) Loven Ind. p. 47. - Jeffreys Br. Conch. III 

 p. 34 T. 47, F. 3. — Sars Norv. p. 83 (Peripl.). — Locard Cat. 

 p. 393. 



Periploma myalis CoIIard de Cherres Act. Soc. Linn. Bord IV p. 12. 



Cochlodesma Leana Caillaud Cat. Loire p. 66, nec Couth. 

 Hab. Oceanum atlanticum. 



6. Tbracia corbuloides Deshayes. T. transverse- 

 ovata, inaequivalvis, valvula dextra gibbosiore, inaequilatera, 

 parte antica parabolice curvata breviore, margine dorsali postico 

 recto, ventrali convexo medio subangulato, extremitate postica 

 biangulata, cristis 3 ex umbone decurrentibus , quarum una 

 margini dorsah proxima, biangulata; unicolor grisea, punctis 

 elevatis sub lente tantum conspicuis aspera; umbones magni, 

 inferior emarginatus; callus ligamentalis angustus; sinus pallialis 

 rotundatus, Vs testa occupans. — Long. 45 Mm. 



Thracia corbuluides Deshaves Lam. VI p. 83. Kiener T. 2,F. 1. 



~ Blaiaville Malacol. T."^ 76, F 7. — Philippi Emim. II p. 16.— 



Reeve sp. 1. — Weinkauff Mittelm p. 38 — Monterosato Enum. 



p. 15. 

 Juv. = Thracia ovalis Philippi teste Monterosato. 



Hab. Mare mediterraneum. 



7. Thracia septentrionalis Jeffreys. T. parva, 

 ovato-triangularis, compressa, alba, solidula, inaequilatera, parte 

 antica elongata, rotundata, postica abrupte truncata; margine 

 dorsali antico hoirzontali, posticodeclivi, ventrali ferehorizontali; 

 lira ex umbonibus ad angulum posticum inferiorem decuiTente; 



