llfi 20 



separated from (he two other forms mentioned above, at any rate as far as the 

 specimens from the Gulf of Siam are concerned. These agree entirely with the 

 diagnosis and figure by Reeve, and also with the excellent description by Edgar 

 Smith of A. sciilptilis. They do not at all resemble the figure of Lamarck's original 

 specimen olA.pisolina (in Journal de Conchyl., vol. 52, 1904, pi. 5, figs. 6—7); neither 

 do they agree with Reeve's diagnosis and figure of his species A. solida. The great 

 number of specimens which I have before me all show a while colour under the 

 thin epidermis. A. Zebuensis, Reeve, is undoubtedly synonymous with A. sciilptilis. 



Area (Fossularca) tenebrica, Reeve. 



Aren tenebrica, Kkevk, Proc. Zool. Soc. London, XII, 1844, p. 126. 



— - — Conctiol. icon., II, Area, Sp. 105. 



— (Barbatia) tenebrica, Rkeve, Martini u. Chemnitz, Conchyl. Cabin., VIII, 2 Abth., p. 156, pi. 39, 



figs. 7-8. 



— — — — Edg. a. Smith, Report on tlie zoolog, collect, made during tlie voyage 



of H. M.S. "Alert," 1884, p. 110. 



— (Fossularca) — — Lamy, Joiirn. de Conchyl., vol.55, 1907, p. 105. 



Coast of Lem Ngob (1). North end of Koh Chang, 1 fathom, old coral blocks (4). 

 Koh Chang, between stones at very low tide (46). Gulf at the south end of Koh 

 Chang (1). Strand of Koh Kahdat (•/2). 



Long. 7 — 16 mm. 



Distribution: — Bombay, Karachi (Melvill & Standen). — Philippines, 

 Japan (Nagasaki). Port Essington, Port Curtis. 



The epidermis is extremely velvet-like in several of the specimens from the 

 Gulf of Siam, and the outline in this species varies rather considerably. 



Area (Acar) plicata, Ch. 



Area plicata, Chemnitz, Conchyl. Cabin., XI, 1795, p. 244, pi. 204, lig. 2008. 



— {Acar: plicata, Chemnitz, Martini u. Chemnitz, Conchyl. Cabin., VIII, 2 Abth., p. 195, pi. 47, fig. 5. 



— — — — E. Lamy, Bull, du Mus. d'Hist. Nat. Paris, 1904, pp. 274-75. 



— — — — — Journ. de Conchyl., vol. 55, 1907, p. 80. - Hull, du Mus. d'Hist. 



Nat. Paris, 1906, p. 317. 



— squamosa, Lamarck, Anim. sans vert., VI, part. 1, 1819, p. 45, No. 35. — éd. 2, VI, p. 474, No. 35. 



— — — Savigny, Descr. de l'Egypte. Mollusques, pi. 10, fig. 6. 



— — — Lamy, Journ. de Conchyl., vol. 52, 1904, p. 142. 



Barbatia squamosa, Lamarck, Phitchard and Gatliff, Proceed. Roy. Soc. Victoria, vol. 17, part. 1, 1904, 



p. 241. 

 Area Domingensis, — Anim. sans vert., VI, part. 1, 1819, p. 40, No. 16. — éd. 2, VI, p. 467, No. 16. 



— — — Lischke, Japan. Meeres-Conchyl., II, p. 142 u. Ill, p. 107. 



— (Acar) domingensis, Lamarck, Ed. A. Smith, Lamellibranchiata of the Challenger Exped., p. 265. 



— gradata, Uroderip and Sowerby, Zoolog. .Journal, IV, 1829, p. 365. 



— — _ . _ Gray, Zool. of Beechey's Voyage, p. 152, pi. 43, fig. 1. 



— — — - — Hanley, Ree. biv. shells, p. 155, pi. 18, fig. 39. 



— — — - — Reeve, Conchol. icon., II, Area, Sp. 92. 

 Byssoarca divaricata, Sowerby, Proc. Zool. Soc. London, I, 1833, p. 18. 



Area — — Reeve, Conchol. icon. II, Area. Sp. 108. 



