i89 



1903. Arcopagia costata Hidalgo, Obras MalacoL, II, p. 153. 



1905. Arcopagia costata Hidalgo, Cat. Filip., p. 319. 



1928. Tellina [Linearia) costata Faustino, Summary Philippine Mar. Freshvv. MolL, p. 92. 



It is not possible to agrée with Smith's remarks that "there is no likelihood of this 

 charming species being confounded with any other", as he himself confused two quite distinct 

 species T. {P.) costata and T. (P.) pretiosa. In T. (P.) costata there are over forty low, radial 

 ribs separated by narrow interstices, often with still weaker ribs in the interstices, and distinctly 

 crenulated by concentric ribs cutting the surface into squarish areas. On the posterior side from 

 near the angle at the margin the ridges are very weak but equally developed. In T. [P.) pretiosa^ 

 on the other hand, the beautiful "squamate costellae" are separated by very deep interstices, 

 and the concentric ribbing is very feebly marked. Sowerby's figures of the two species illustrate 

 this point quite clearly. 



Tellina [Arcopagia) habrotima Melvill ^) from the Angrias Bank, Arabian Sea is, as I 

 hâve satisfied myself from an examination of the type of the species, based on a full grown 

 shell of T. [P.) costata. 



Distribution : — T. (P.) costata has so far been recorded from the Philippines and the 

 Arabian Sea. 



The "Siboga" Expédition collected shells of this species at Macassar (St. 71) and Anchorage 

 off Beo, Karakelang Islands (St. 131). 



18. Tellina [Pseudarcopagia) pretiosa Deshayes. 



1854. Tellina pretiosa Deshayes, Proc. Zool. Soc. London, p. 360. 



1856. Tellina [Arcopagia) pretiosa Adams, H. & A., Gen. Rec. MolL, II, p. 397. 



1868. Tellina [Arcopagia) pretiosa Tryon, Amer. Journ. Conch., IV, p. 91. 



1869. Tellina pretiosa Sowerby in Reeve, Conch. Icon., XVII, Tellina, pi. LVI, fig. 329. 

 1878. Arcopagia pretiosa Bertin, Nouv. Arch. Mus. d'Hist. Nat. Paris, (2) I, p. 325. 



1885. Tellina [Arcopagia) pretiosa Smith (ex parte), "Challenger" Lamellibranchia, p. 104. 



1890. Tellina [Arcopagia) pretiosa Paetel, Cat. Conch. Samm., III, p. 49. 



1896. Tellina [Arcopagia) pretiosa Casto de Elera, Cat. Sist. Filip., p. 725. 



1903. Arcopagia pretiosa Hidalgo, Obras MalacoL, II, p. 153. 



1905. Arcopagia pretiosa Hidalgo, Cat. Filip., p. 320. 



1928. Tellina [Linearia) pretiosa Faustino, Summary Philippine Mar. Freshw. MolL, p. 93. 



I hâve discussed the différences between T. [P^ pretiosa and T. [P.) costata in my remarks 

 on the latter species. The shell of T. [P.) pretiosa in the young stages resembles that of T. [P.) 

 costata, but the sculpture enables one to separate the two species without any difficulty. 



Distribution: — T. [P.) pretiosa is found in the Philippines and round Fiji. 



The "Siboga" Expédition collected shells of this species at the Anchorage off Djangkar, 

 Java (St. 4), Bay of Pidjot, Lombok (St. 33), Kambaragi Bay, Tana Djampeah (St. 64), west of 

 Kwandang Bay entrance (St. 116), Anchorage off Lirung, Salibabu Island (St. 133), Anchorage 

 off Laiwui, coast of Obi Major (St. 142), between the Islands of Wowoni and Buton, northern 

 entrance of Buton Strait (St. 204), Anchorage south of Lucipara Group (St. 225) and Anchorage 

 east of Dangar Besar, Saleh Bay (St. 313). 



i) Melvill, J. C. — Mem. Proc. Manchester Lit. Phil. Soc, XLII, N" 4, p. 34, pi. q, fig. 8 (i 



