43 



1893- Barbatia decnssata Stearns, Expl. "Albatross", p. 421. 



1895. Arca [Barbatia) decnssata Pilsbry, Cat. Mar. Moll. Japan, p. 149. 



1896. Barbatia decnssata Casto de Elera, Cat. sist. Filip., p. 802. 



1899. Barbatia decnssata Melvill & Standen, Journ. Litin. Soc. London (Zool.), XXVII, p. 185. 



1901. Barbatia decnssata Sturany, Denkschr. Akad. Wiss. Wien, (Math.-Nat.), LXIX, p. 289. 



1901. Barbatia decnssata Fischer, H., Journ. Conchyliol. XLIX, p. 219. 



1901. Barbatia decnssata Suter, Trans. N. Z. Inst., XXXIV, p. 223. 



1904. Arca [Barbatia] decnssata Lamy, Bull. Mus. d'Hist. Nat. Paris, X, p. 273. 



1904. Arca trapezina Lamy, Journ. Conchyliol., LU, p. 142, pi. V, figs. 4, 5. 



1905. Arca decnssata and A. trapezina Hidalgo, Cat. Filip., pp. 372, 374. 



1906. Arca decnssata Owston, Japan. Loochooan Shells, p. 33. 



1906. Arca [Barbatia) decnssata Lamy, Bull. Mus. d'Hist. Nat. Paris, XII, p. 317. 

 1906. Barbatia decussata Standen & Leicester, Ceylon Pearl Oyster Rept., V, p. 291, 



1906. Barbatia decnssata Dautzenberg, Journ. Conchyliol., LIV, p. 29. 



1907. Barbatia decnssata Suter, Trans. New Zealand Inst., XXXIX, p. 265. 



1907. Arca [Barbatia) decussata Lamy, Bull. Mus. d'Hist. Nat. Paris, XIII, p. 153. 



1907. Arca [Barbatia) decnssata Lamy, Journ. Conchyliol., LV, p. 65. 



1909. Arca [Barbatia) decussata Melvill, Trans. Linn. Soc. London, (Zool.), XIII, p. 121. 



1909. Arca [Barbatia) coviplanata Lynge (ex parte, non Chemnitz), D. Kgl. Dansk. Vidensk. 



Selsk. Skr. Nat.-Math., (7) V, p. m. 



1910. Arca decnssata Hedley, Austral. Ass. Adv. Sci., XII, p. 344. 



1910. Arca [Barbatia) decnssata Dautzenberg, Journ. Conchyliol., LVIII, p. 30. 



1911. Arca decussata Pelseneer, "Siboga" Lamellibranches (Anat.), p. 11, pi. II, figs. 8 — ii, 13; 



pi. III, figs. 3, 14. 



1916. Arca [Barbatia) decnssata Boettger, C. R., Abhandl. Senckenberg. Naturf. Gesellsch., 



XXXVI, p. 307. 



1917. Arca decussata Thiele, Voeltzkow Reise in Ost-Afrika, III, p. 564. 



1917. Arca [Barbatia) decnssata Lamy, Bull. Mus. d'Hist. Nat. Paris, XXII, p. 131. 



1917. Arca decnssata Odhner, Kungl. Sv. Akad. Handl., LU (N*^ 16), p. 8. 



1923. Arca [Barbatia) decnssata Oostingh, Senckenbergiana, V, p. 108. 



1929. Arca [Barbatia) decnssata and var. Petersi Dautzenberg, Faun. Colon. Français., III, p. 575. 



After carefuUy going through the earlier descriptions and the collections in the Indian 

 Muséum, Calcutta, and the Reevian types in the British Muséum (Natural History), London, I 

 hâve corne to the conclusion that the limits assigned by Lamy to this species and to A. nivea 

 are probably correct, and that Lynge, while treating A. lima as a distinct species, was wrong 

 in uniting A. velata with A. decttssata. I hâve no doubt that Lamarck's spécimen of A. trapezina 

 which was figured by Delessert and Dunker's A. stiginosa, A. oblonga and A. petersi are ail 

 to be referred to A. deaissata. 



Distribution: ■ — A. decussata is widely distributed in the Indo-Pacific Océan, and is often 

 found attached to other molluscs. 



In the "Siboga" collection it is represented by a fair séries of shells from the Bay of 

 Pidjot, Lombok (St. 33), Coral Reef otf Labuan Pandan, Lombok (St. 34), Paternoster Island 

 (St. 37), Bay of Bima (St. 47), Corals near the Shore at Pulu Kaniungan (St. 89), Tawi-Tawi 

 Island (St. 93), off North Ubian (St. 99), off Sawan, Siau Island (St. 125), off Kavvio and 

 Kamboling Islands (St. 129), off Beo, Karakelang Islands (St. 131), Wunoh Bay, Waigeu Island 

 (St. 152), Waru Bay, north coast of Ceram (Stat. 174), South of Lucipara group (St. 225'=), Ambon 

 Anchorage (St. 231), off Kilsuin, Kur Island (St. 250), Tuai Anchorage, Kei Island (St. 258), 

 Elat, West coast of Great Kei Island (St. 261), Kulewatti Bay, Dammer Island (St. 277), near 

 Timor (St. 282), Reef at Sapeh Bay (St. 311) and east of Dangar Besar, Saleh Bay (St. 313). 



