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 (*/2). 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 Isls.), Lifu (Loyalty Isls.), Funafuti (Ellice Isls.). 
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. 
— — — Puiippl, Abbild. u. Beschreib. neuer od. wenig gekannt. Conchyl., Il, 1847, 
p- 179, Cytherea, pl. 5, fig. 2. 
Cytherea — — Sowersy, Thesaur. conchyl., II, p. 641, No. 102, pl. 134, fig. 147. 
Circe — -- REEVE, Conchol. icon., XIV, Circe, Sp. 33. 
Lioconcha = — Romer, Monogr. d. Moll. Venus, I, p. 166, pl. 46, fig. 2. 
Koh Mak, sandy coast (*/2). The strand of Koh Kahdat (*/2). 
Long. 11—27 mm. 
Distribution:— Singapore, Andamans, Ceylon. — Philippines, Viti Isls. 
HipauGo” regards Lioconcha Sphragitis, Romer,* as a variety of the present 
species. 
Circe (Lioconcha) sulcatina, Lam. 
Cytherea sulcatina, Lamarck, Hist. nat. d. anim. s. vert., V, 1818, p. 568, No. 29. — éd. 2, VI, p. 308, No. 29. 
Cytherea = — Sowersy, Thesaurus Conchyl., I], p.641, No. 101, pl. 134, figs. 145—46. 
Circe — — REEVE, Conchol. icon., XIV, Circe, Sp. 40. 
Cytherea (Lioconcha) sulcatina, Lamarck, ROMER, Monogr. d. Molluskengatt. Venus, I, p. 165, pl. 46, fig. 1. 
1, Prerrrer in Martini u. CHemnitz, Conchyl. Cabin., XI Bd., 1 Abth., 1869, p. 39. — A.H. Cooke, 
Annals and Magaz. Nat. Hist. 1886, Ser. 5, vol. 18, p.101. — Casro pe Evera, Fauna de Filipinas, III, p. 
743. — Epa. A. Smiru, Rep. on the Lamellibranchiata of the Challenger Exped., pp. 146—47. — Epvy. v. 
Marrens, Rumphius Gedenkboek, 1902, p.125 (17). 
2 HrpaLeo, Obras malacologicas, I, Tome II, 19038, p. 220. 
3 Romer, Monogr. d. Moll. Venus, I, p. 162, No. 13, pl. 43, fig. 3. 
D. K. D. Vidensk. Selsk. Skr., 7- Reekke, naturvidensk. og mathem. Afd. V. 3. 30 
