85 



Distribution: — /. attenuata bas been recorded from the Red Sea to the Australian waters. 



In the "Siboga" Expédition collections there are 3 young shells from the Bay of 

 Kankamaraân, S. coast of Kangeang (St. 16), Bay of Badjo, W. coast of Flores (St. 50) and the 

 Anchorage between Nusa Besi and the N. E. Point of Timor (St. 282). The shell from St. 282 

 is very young and is doubtfully assigned to this species. 



5. Isognomon perna (Linn.). 



1685. Pecten leviter cavits etc. Lister, Hist. Conch., pi. CCXXVIII, fig. 63. 



1753. Ostreum laeve Klein, Test. Meth. Ostra., p. 124, pi. VIII, fig. 20. 



1767. Ostrea Perna Linnaeus, Syst. Nat., (éd. XII), p. 1149. 



1786. Ostrea Perna Schrôter, Einleit., III, p. 351, pi. IX, fig. 5. 



1790. Ostrea Perna Gmelin, Syst. Nat., (éd. XIII), p. 3338. 



18 17. Ostrea perna Dillvvyn, Descr. Cat., I, p. 281. 



1819. Perna sulcata Lamarck, Anim. sans Vertèb., VI, p. 141. 



1823. Perna sulcata Sowerby, Cat. Tankerville, p. 24. 



1824. Perna sulcata Dubois, Epitome, p. 109. 



1832. Perna sulcata Deshayes, Encyclopéd. Méthod., III, p. 737. 



1836. Perna sulcata Deshayes in Lamarck, Anim. sans Vertèb., VII, p. j'j. 



1841. Perna sulcata Sganzin, Coq. Ile France, p. 10. 



1843. Perna Sulcata Hanley, Rec. Biv. Shells, p. 258. 



1845. Perna sulcata Catlow & Reeve, Conch. Nomencl., p. jj. 



1850. Perna sulcata Deshayes in Cuvier, Règne Anim., pi. LXXXI, figs. 3, ^a. 



1850. Perna ereinita Gould, Proc. Boston Nat. Hist. Soc, III, p. 311. 



1852. Perna eremita Gould, U.S. Expl. Exped., p. 446, pi. XL, figs. 557, « — d. 



1855. Ostrea perna Hanley, Ipsa Linn. Conch., p. 117, pi. II, fig. 7. 



1855. Perna sulcata Berge, Conchylienbuch, p. 88, pi. XII, fig. 3. 



1857. Isognomon perna Adams, H. & A., Gen. Rec. Moll., II, p. 527. 



1858. Perna limoides Reeve, Conch. Icon., XI, Perna, pi. IV, fig. 17. 

 1858. Perna sulcata Fischer, P., Journ. Conchyliol., VII, p. 340. 

 1860. Ostrea Limoides Reeve, Elem. Conch., II, p. 66. 



1862. Ostrea eremita Gould, Otia Conch., p. 92. 



1869. Perna Linnaei Duaker, Cat. Mus. GodelTroy, IV, p. 115. 



1882. Melina perna Dunker, Ind. Moll. Mar. Japon., p. 230. 



1887. Perna costellata von Martens (nec Conrad), Journ. Linn. Soc. London (ZooL), XXI, p. 204. 



1890. Pe7'na eremita P. Limoides, P. perna- and P. sulcata Paetel, Cat. Conch. Samm., III, 



pp. 206, 207. 



1891. Perna limoides Clessin in Martini-Chemn. Conch. -Cab. (N. F.), VIII (i), Malleacea, p. 39, 



pi. XIV, fig. 3. 

 1895. Perna perna Pilsbry, Cat. Mar. Moll. Japan, p. 147. 

 1900. Melina perna Smith, Proc. Zool. Soc. London, p. 118. 

 1903. Melina perna Smith, Fauna Geogr. Maldive, Laccadive Archipel., p. 623. 

 1906. Perna perna Owston, Japan. Loochooan Shells, p. 34. 



1909. Perna sulcata Melvill, Trans. Linn. Soc. London (Zool.), XIII, p. 125. 



1910. Perna perna Smith, Ann. Natal Mus., II, p. 218. 



191 1. Isognomum perna Pelseneer, "Siboga" Lamellibranches (Anat.), p. 26, pi. VII, figs. 3 — 8. 

 1929. Isognomon perna Dautzenberg, Faun. Colon. Français., III, p. 567. 



Hanley noted that the type spécimens of Perna sulcata Lamarck preserved in the Muséum 

 d'Hist. Nat. Paris are identical with the Linnean Ostrea perna. 



I. perna is a very variable species. The young shells are thin, but full grown shells are 

 moderately thick, ovate to orbicular in outline, and covered with a large number of slightly 

 raised brownish ribs. 



