44 



3- Arca [Barôatia) decussata Sowerby var. lima Reeve. 



1844. Arca lima Reeve, Conch. Icon., II, Arca, pi. XV, fig. lOi. 



1844. Arca lima Reeve, Proc. Zool. Soc. London, p. 125. 



1847. Arca granulata Philippi, Abbild. Beschreib. Conch., III, p. 114, Arca, pi. VI, fig. 3. 



1848. Arca Griffithiana Nyst., Mém. Acad. Roy. Belgique, XXII, p. 34. 

 1857. Arca [Barbatia) lima Adams, H. & A., Gen. Rec. MolL, II, p. 535. 

 1860. Arca lima Reeve, Elem. Conch., II, p. 93. 



1865. Barbatia lima Angas, Proc. Zool. Soc. London, p. 655. 



1884. Arca {Barbatia) lima Smith, Rep. Voy. "Alert"', p. 1 10. 



1885. Arca [Barbatia) lima Smith, "Challenger" Lamellibranchia, p. 260. 



1889. Arca [Barbatia) lima and A. [B.) granulata Kobelt in Martini, Chemn. Conch. -Cab. 



(N. F.), VIII (2), Arca, p. 115, pi. XXX, figs. 5, 6, p. 116, pi. XXX, figs. 7, 8. 

 1891. Arca [Barbatia) lima Smith, Proc. Zool. Soc. London, p. 431. 

 1896. Barbatia lima Casto de Elera, Cat. Sist. Filip., p. 803. 



1898. Barbatia lima Melvill & Standen, Journ. Conch., IX, p. 81. 



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



1903. Arca [Barbatia) lima Smith, Faun. Geogr. Maldive Laccadive Archipel., II, p. 624. 



1904. Arca helblingi Lamy (ex parte), Journ. ConchylioL, LV, p. 66. 



1906. Barbatia [Barbatia) lima Standen & Leicester, Ceylon Pearl Oyster Rept., V, p. 291. 



1907. Arca [Barbatia) decussata var. lima Lamy, Journ. ConchylioL, LV, p. 66. 



1909. Arca [Barbatia) lima Lynge (ex parte), D. Kgl. Dansk. Vidensk., Skr. Nat.-Math., 



(7) V, p. 113. 

 1917. Arca [Barbatia) lima Lamy, Bull. Mus. d'Hist. Nat. Paris, XXIII, p. 31. 



A single spécimen collected from Sapeh Bay, east coast of Sumbawa (St. 311) agrées 

 so closely with the type of A. lima Reeve, that I hâve no hésitation in referring it to that 

 species. In référence to whether the form lima is distinct from or only a variety of A. dectissata 

 I hâve followed Lamv, as I hâve not enough material to settle this question. 



4. Arca [Barbatia) grayana Dunker. 



1868. Arca Grayana Dunker, Novitat. Conch., Moll. Mar., p. 92, pi. XXXI, figs. 5 — 7. 



1869. Barbatia Grayana Dunker, Cat. Mus. Godefïroy, IV, p. 114. 



1889. Arca [Barbatia) Grayana Kobelt, in Martini Chemn., Conch. Cab., (N. F.), VIII, (2), 



Arca, p. 129, pi. XXXIII, figs. 7, 8. 



1890. Barbatia grayana Paetel, Cat. Conch. Samm., III, p. 213. 

 1907. Arca Grayana Lamy, Journ. ConchylioL, LV, p. 68. 



1911. Arca Grayana Pelseneer, "Siboga" Lamellibranches (Anat.), pi. II, fig. i. 



Lamy when writing his revision of the family had apparently no spécimens of this interesting 

 species for he makes only a passing référence to it in his account of A. decussata. Dunker 

 published a good description and figures of the species, but only gave the rather indefinite 

 habitat — Indian Océan — for it. 



The ".Siboga" collection contains 4 shells, w^hich I refer to Dunker's species and the 

 following notes on them should prove useful for the identification of the species hereafter. 



The shell is oblong, somewhat compressed, solid, slightly inequilateral, rounded anteriorly, 

 subtruncated posteriorly, ventral margin straight or sometimes arched upwards. The sculpture 

 consists of very closely placed rounded to rhomboidal nodules formed by the intercrossing of 

 the fine radial and concentric ribs which run very closely and regularly over the entire surface; 



