Ci'RENA. — B.VTISSA. 207 



conical and the posterior are somewhat elonfi;ated and flattened. 

 The striiv are more or less obsolete. The epidermis is liglit green 

 and polished. The ligament is narrow, elongated, and not 

 prominent." 



The only specimens of this species Mhich the author has been 

 able to see are those in the British Museum, two in number, 

 Avhich, though they agree well with Prime's description and figure, 

 are much smaller, having somewhat the appearance of young 

 specimens ; their measurements being as below : - 



1. 2. 



Long 43 46 mm. 



Lat 47-5 49 mm. 



Diani 24 24-.") mm. 



331. Cyrena galatheae {JliJrcJi). 



Cyrena {('or/icori/c/as) (;aIathc(T (Reinhfirdt MS,), Miircli, Cat. 



Couch. Kierulf, 1850. 'p. -'32, pi. 2. 

 Cyrena yalathea, Prime. Cat. Corb., 186:5, p. 6 ; 18G9-70. p. 144, 



no. o-'j. 



Original description : — Testa cordato-trigona, ina-quilatera, 

 turgida, concentrice striata, postice longiore, truiicata, antice et 

 inferne angnlata, umbonibus distantibus, prominentibus ad -j 

 auter. sitis ; lunula rhomboidali, medio earinata ; area lanceolata, 

 convexa, ligamento tumido duplo longiore. Dentibus lateralibus 

 interne fovea impressa ; d. 1. posteriore v. sin. triaugulari 

 compresso ; pone ligamentum sito ; d. lunulari v. s. conico, 

 dentibus cardiualibus aproximato. Dentium cardinalium 2 

 aiiterioribus v. s. et 2 posterioribus v. d. bifidis, dente card, 

 posteriore v. s. lineari, v. d. obsoleto. Limbo augusto, nitido. 

 Impressione musculari semilunari, posteriore rhomboidali, duplo 

 maiore. Colore albo, dentibus cardiualibus et fundo cavitatis 

 flavescentibus. Epidermide nigrescente, antice radiis obsolotis. 



Long. 100, lat. 120, diam. 74 mm. 



Ilab. Galatea Eiver, JSTicobar Islands. 



Genus BATISSA. 



Batism, Gray, A. M.N. H. ser. 2, xi, 18o3, p. 38. 



Cyprina. Cyclas, Bruguiere, Encycl. Meth. 1792. 



Cyrena, Lamarck, Auim. s. Vert, v, 1818, p. 553. 



TeHMS, Oray, in AVood, Index Test., Suppl. 1828, pi. 2, fig. 13: 

 DeshavesJ Cat. Brit. Miis. 1854, p. 219: Prime, Cat. Corbiculid:e, 

 1869-70. p. 138; Clessin. in Martini X: Chemnitz, Conch. Cab. 

 1879, p. 206. 



Type, Batissa tenebrosa. Hinds, from the I'iji Islands. 

 Kcuufe. Xicobar Islands ; ^Nlalay Archipelago ; N. Australia and 

 Tropical Islands of the Pacific. 



