226 130 



Caecella Cumingiana, Desh. 



Cœcella Cumingiana, Deshayes, Proc. Zool. Soc. London, XXII, 1854, p. 334, No. 78. 



— — -- Hidalgo, Fauna malacolog. d. I. isl. Filipinas, II, p, 60, No. 123. 



Koh Chang (14). Coast of Koh Chang (1). 



Long. 10—26 mm. 



Distribution:— Philippines. 



I have at my disposal some specimens of C. Cumingiana, Desh., from the 

 Philippines which were contributed by Cuming himself; they are somewhat larger 

 than the specimens from the Gulf of Siam, but otherwise exactly correspond with 

 them. The epidermis in the small individuals (measuring as much as 23 mm. in 

 length) is pale yellow, while in older individuals it is brownish. It will undoubtedly 

 be proved in the future that the series of species established by Deshayes of the 

 genus Caecella, can be considerably reduced. 



Fam. Veneridae. 



Cytherea (Meretrix) meretrix L. 



Venus Meretrix, Linné, Syst. Nat., ed. X, 1758, p. 686, No. 102. — ed. XII, p. 1132, No. 127. — Mus. Ludovicæ 



Ulricæ reg., p. 501, No. 60. 

 Cytherea meretrix, Linné, Lischke, Japanische Meeres-Conchylien, I, pp. 122 — 26. 

 Meretrix — — Dautzenberg et Fischer, Journ. de Conchyl., vol. 53, 1905, p. 216. 



Venus lusoria, Chemnitz, Conchyl. Cabin., VI, 1782, p. 337, pi. 32, fig. 340. 



Meretrix — — Römer, Monogr. d. Molluskengatt. Venus, 1, p. 30, pi. 12, fig. 1; pi. XI, flgs. 1—2. 



Cijtiierea petechialis, Lamarck, Hist. nat. d. anim. s. vert., V, 1818, p. 561, No. 2. — éd. 2, VI, p. 299, No. 2. 

 Meretrix — — Römer, Monogr. d. Molluskengatt. Venus, I, p. 29, pi. 9, fig. 1. 



Venus zonaria, — Hist. nat. d. anim. s. vert., V, 1818, p. 562, No. 5. — éd. 2, VI, p. 299, No. 5. 



— impudica, — Hist. nat. d. anim. s. vert., V, 1818, p. 561, No. 3. - éd. 2, p. 299, No. 3. 



North coast of Koh Chang (1). 



Long. 51 mm. 



Islands in the Gulf of Siam (M. petechialis, Lam. — L. Morlet). "Siam" 

 (M. impudica, Lam., M. zonaria, Lam. — E. v. Marten.s). 



Distribution:— Singapore, Salang (Malacca), Nicobars, Ceylon, Bombay, 

 Aden. — Annam, Tonkin, China, Formosa, Japan, Liukiu Isis., Philippines, Borneo, 

 Java, Timor, Moluccas. ("Mazatlan," Carpenter ; without doubt the determination 

 is erroneous). 



The specimen from Koh Chang belongs to the form zonaria, Lam. The many 

 different species which have been established by Lamarck and other authors on 

 the basis of the present species, have for a long time rendered its determination 

 difficult, and Lischke (loc. cit.) was the first to demonstrate, and that correctly, 

 that all these forms belong to the same species. In spite of this, many later authors 

 have persisted in maintaining the varieties as species, a view which is quite unten- 

 able when larger series and specimens in various ages are at hand for investigation. 



