The shell figured by Reeve ^) as Dione pellucida (Lamarck) is also a spécimen of Pitar 

 affinis, but I am not sure wether the Lamarckian species ") was correctly interpreted by Reeve. 



P . affinis is closely allied to P. obliqîiata (Hanley ^) ), but the shell of the latter is much 

 thicker, heavier, more strongly inflated, very oblique, with the umbones lying almost near the 

 anterior end and the posterior margin much more strongly arched. 



Distribution : — P . affi-nis is widely distributcd in the Indo-Pacific Région. 



The "Siboga" Expédition collected only young shells of the species in the Bay of Bima 

 (St. 47), Haingsisi, Samau Island, Timor (St. 60), Buka or Cyrus Bay, south coast of Rotti Island 

 (St. 299) and the Anchorage east of Dangar Besar, Saleh Bay (St. 313). 



Genus Circe Schumacher. 



18 17. Circe Schumacher, Essai Nouv. Syst., p. 152. 



1838. Circe Gray, Analyst, VIII, p. 307. 



1853. Circe Rômer, Krit, Untersuch., p. 15. 



1857. Circe Adams, H. & A., Gen. Rec. Moll., II, p. 428. 



1864. Circe Reeve, Conch. Icon., XIV, Circe, pi. I (explanation). 



1869. Circe Rômer, Mon. Venus, I, p. 192. 



1887. Circe Fischer, P., Man. Conchyliol., p. 1080. 



1902. Circe Dali, Proc. U.S. Nat. Mus., XXVI, p. 351. 



1903. Circe Dali, Trans. Wagner Free Inst. Sci. Philadelphia, III, p. 1250. 

 19 14. Circe Jukes-Browne, Proc. Malacol. Soc. London, XI, p. 6Ç). 



I consider Circe Schumacher to be of the same rank as Gafrarium Roding. The géno- 

 type of Circe is Circe scripta (Linn.). 



I. Circe scripta (Linn.). 



1741. Chaîna litterata rotnnda Rumph, Amboin. Rarit., p. 140, pi. XLIV, fig. C, 



1742. CJiama Optica Riimphi d'Argenville, Hist. Nat., pp. 320, 325, pi. XXIV, fig. M. 

 1742. Coucha marina, etc., Gualtieri, Ind. Test., pi. LXXVII, fig. C. 



1758. Venus scripta Linnaeus, Syst. Nat., (éd. X), p. 689. 



1764. Venus scripta Linnaeus, Mus. Lud. Ulr., p. 507. 



1767. Venus scripta Linnaeus, Syst. Nat., (éd. XII), p. 1135. 



177 1. L'Ecriture arabique bâtarde Knorr, Délices Yeux, V, p. 26, pi. XV, fig. 3. 



1784. Venus scripta Linnaei, Chemnitz, Conch. Cab., VII, p. 31, pi. XL, figs. 420 — 426. 



1788. Venus scripta Schrôter, Conch. -Cab. Namen Reg., p. ii2. 



1790. Venus scripta Gmelin, Syst. Nat., (éd. XIII), p. 3286. 



1797. Bruguière, Encyclopéd. Méthod., pi. CCllXXIV, fig. i. 



1797. Pectunculus scriptus Humphrey, Mus. Calonnianum, p. 48. 



1798. Cytlierea scripta Roding, Mus. Boltenianum, p. 178. 

 1802. Venus scripta Bosc, Hist. Nat. Coq., III, p, 68. 



18 17. Venus scripta Dillwyn, Descr. Cat., I, 201. 



18 17. Circe violacea Schumacher, Essai Nouv. Syst., p. 152, pi. XV, figs. 3 â:, b. 



1818. Cytlierea scripta and C. undatina Lamarck, Anim. sans Vertèb., V, p. 575, 



1824. Cytheria (sic) undatina and C. scripta Dubois, Epitome, pp. 70, 71. 



1825. Cytlierea scripta Sowerby, Cat. Tankerville, p. 13. 



1830. Cytlierea scripta Deshayes, Encyclopéd. Méthod., II, p. 58. 



1835. Cytlierea scripta and C. undatina Deshayes in Lamarck, Anim. sans Vertèb., VI, p. 320. 



i) Reeve, L. — Conch. Icon., XIV, Dione, pi. XI, fig. 48 (1863). 



2) Lamarck, J. B. — Anim. sans Vertèb., V, p. 571 (1818). 



3) Hanley, S. — Proc. Zool. Soc. London, p. 109 (1844). 



