137 233 



Gulf of Rayong, 7—10 fathoms, sand and mud (10). N. of Koh Kam, 5 fathoms, 

 gravel (2). Between Koh Mesan and Cape Liant, 9 fathoms (2). Koh Kahdat, 1 — 10 

 fathoms, sand, mud (23). Koh Mak, sandy coast ('/s). W. of Koh Kut, 15 fathoms, 

 mud (5). 



Long. 3 — 32 mm. 



Distribution: — Andamans, Ceylon, Karachi, Persian Gulf, Laccadive and 

 Maldive Archip., Red Sea, Obok (Aden), Tadjurah Bay, Mauritius, Rodrigues, Dur- 

 ban (Natal). — Philippines, China, Japan, Blitong (post-tertiary), Torres Strait, Upolu 

 (Samoa Isis.), Lifu (Loyalty Isis.), Funafuti (EUice Isis.). 



The individuals from the Gulf of Siam are all covered with a pale, rather 

 thick, tallow-like epidermis, which is, however, usually somewhat worn off upon 

 the umbones; the specimens agree in outline and colour more nearly with Reeve's 

 figures. As the limits of the variation of this species are not fixed, authors' have, 

 in course of time, had very variable opinions regarding it and also as to how far 

 several other forms should be referred to this species; it varies greatly both in 

 outline and colour, and many closely allied forms, which are designated as species, 

 will unquestionably prove to be only varieties and local forms, which is also 

 indicated by the somewhat scattered distribution of the species, as far as it is at 

 present known. 



Circe (Lioconcha) trimaculata, Lam. 



Cytherea trimaculata, Lamarck, Hist. nat. d. anim. s. vert., V, 1818, p. 571, No. 41. — éd. 2, VI, 1835, 



p. 313, No. 41. 

 — — — Philippi, Abbild, u. Beschreib, neuer od. wenig gekannt. Conchyl., II, 1847, 



p. 179, Cytlierea, pi. 5, fig. 2. 

 Cytherœa — — Sowerby, Thesaur. conchyl., II, p. 641, No. 102, pi. 134, fig. 147. 



Circe — — Reeve, Gonchol. icon., XIV, Circe, Sp. 33. 



Lioconcha — — Römer, Monogr. d. Moll. Venus, I, p. 166, pl. 46, fig. 2. 



Koh Mak, sandy coast (^/s). The strand of Koh Kahdat ("/i). 

 Long. 11—27 mm. 



Distribution: — Singapore, Andamans, Ceylon. — Philippines, Viti Isis. 

 Hidalgo'-' regards Lioconcha Sphragitis, Römer,-' as a variety of the present 

 species. 



Circe (Lioconcha) sulcatina, Lam. 



Cytlierea sulcatina, Lamarck, Hist. nat. d. aiiira. s. vert., V, 1818, p. 568, No. 29. — éd. 2, VI, p. 308, No. 29. 

 Cytherœa — — Sowerby, Thesaurus Conchyl., II, p. 641, No. 101, pl. 134, figs. 145 — 46. 



Circe — — Reeve, Conchol. icon., XIV, Circe, Sp. 40. 



Cytherea (Lioconcha] sulcatina, Lamarck, Römer, Monogr. d. Molluskengatt. Venus, 1, p. 165, pi. 46, fig. 1. 



* L. Pfeii FEii in Martini u. CnEMNrrz, Conchyl. Cabin., XI Bd., 1 Abth., 1869, p. 39. — A. H. Cooke, 

 Annals and Magaz. Nat. Hist. 1886, Ser. 5, vol.18, p. 101. — Casto de Elera, Fauna de Filipinas, III, p. 

 743. — Edg. a. Smith, Rep. on the Lamellibranchiata of the Challenger Exped., pp. 146 — 47. — Edv. v. 

 Martens, Rumphius Gedenkboek, 1902, p. 125 (17). 



- Hidalgo, Obras malacologicas, I, Tome II, 1903, p. 220. 



3 RÖMER, Monogr. d. Moll. Venus, I, p. 162, No. 13, pl. 43, fig. 3. 



U. K. D. VIdensk, Selsk. Slir., 7. Hække, n.-iturviilensk. o« nialhem. Aid. V. 3. 30 



