252 156 



circular, convex, white, rather thin; umbones high and situated at the middle of 

 the axis of the shell. Apex turning towards the anterior end. The whole surface 

 covered with a network of close-set, fine, parallel lines, which cross each other; 

 they proceed from the umbones and from the upper sides and radiate outwards 

 towards both ends and towards the ventral side. Upon each valve there is a large, 

 elongated, crescent-formed lunule, circumscribed by a groove; it is glossy, destitute 

 of network sculpture, and striped only by the lines of growth; the brown ligament 

 is external. The interior of the valves is glossy, milky white; in the right valve 

 there are two diverging cardinal teeth of which the posterior is bifid; in the left 

 valve there are three cardinal teeth of which the central and largest is bifid. The 

 margin is smooth. The sinus is high and widely triangular. 



Note. Clementia papyracea, Gray, has been taken at Singapore in shallow 

 water (by Sv. Gad). 



Venerupis Irus L. 



Donax Irus, Linné, Syst. Nat., ed. XII, 1767, p. 1128, No. 111. 



Venenipis Irus, Linné, L. Pfeiffer in Martini u. Chemnitz, Conchyl. Cabin., XI Ud , 1 Abth., 1869, p. 

 245, pi. 31, figs. 17-19. 



— irus, — BucguoY, Dautzenberc, et Doli.fus, Moll. mar. de Roussillon, II. p. 438, pi. 67, 



figs. 9 — 18. 



— macropbylla, Deshayes, Catal. of the Concliifeia in tlie coll. of the British Museum, I, 1853, 



p. 193. — Proc. Zool. Soc. London, 1853, Moll. pi. XVIII, fig. 8. 



— — — SowERBY, Thesaur. Conchyl., II, p. 763, No. 2, pi. 165, fig. 20. 



— — — SowERBY in Reeve, Concliol. icon., XIX, Venerupis, Sp. 23. 

 Rupellaria — — Pagenstecher, lieber d. v. Kossmann am Rothen Meere ges. Moll. 



1877, p. 42, No. 35. 



— — — Rochebrune, Mater, pour la faune de l'Archipel du Cap Vert. Nouv. 



Arch, du Muséum, 2 Sér., Mémoires, IV, p. 255, No. 34. 

 Venerupis — — A.H.Cooke, Ann. and Mag. Nat. Hist., 1886, p. 103. 



Irus — -, — Mei-vii.l and Standen, Journ. of Conchol., IX, p. 84. 



Venerupis — — Hidalgo, Fauna malacol. de I. Isl. Filipin., II, p. 321, No. 417. 



— derelicta, — Proc. Zool. Soc. London, 1853, p. 4, No. 17. 



— — — Sowerby. Thesaur. Conchyl., II, p. 765, No. 9, pi. 164, fig. 16. 



— — — — in Reeve. Conchol. icon., XIX, Vencrupis, Sp. 8. 



— — — Hidalgo, Fauna raalacol. de I. Isl. Filipin., II, p. 320, No. 415. 



— fimhriata, Sowerby, Thesaur. Conchyl., II, 1855, p. 766, No. 12, pi. 165, fig. 23. 



— — — in Reeve, Conchol. icon., XIX, Venerupis, Sp. 25. 

 attenuata, — Reeve, Conchol. icon., XIX, Venerupis, Sp. 7. 



Koh Mesan, 15 fathoms, stones (%). Between Koh Mesan and Cape Liant, 

 5—9 fathoms, sand ('/a). Coast of Lem Ngob, low tide, stones {■'h). North end of 

 Koh Chang, 1 fathom, coral blocks (1). Koh Chang, 1—2 fathoms, old coral blocks (6). 

 Koh Kahdat {Va). 



Long. 1 — 14 mm. 



Distribution: — Singapore (shallow water, Sv. Gad), Madras, Bombay, Persian 

 Gulf, Karachi, Aden, Red Sea, Suez, Mediterranean, Black Sea, Atlantic Ocean (the 

 coast of Europe from England and Ireland to Cape Vert), Mauritius. — Annam 

 (V. attenuata, Sow.), Philippines, Japan, Aru Isl. {V. attenuata, Sow.), Funafuti Atoll. 



