BIVALVE SHELLS. 247 



umbonibus distantibus, prominentibus ; lunula rhomboidali, 

 medio carinata ; area lanceolata, convexa ; ligaraento tumido, 

 longiore, valvis intus albis, cardine forniceque flavescentibus ; 

 epidermide nigrescente, antice obsolete radiata ; dentibus late- 

 ralibus brevibus, antico conico iutrante, postico oblongo. 



Cyi'ena Galatbese, Morch, Cat. Conch. Kierulf. -p. 32. t.2; Zeitsch. 

 fur Malac. no. 8. p. 128. 



Hab. In insula Nicobar, fluv. Galatheae. 



17. Cyrena cyprinoides. 



C. testa magna, turgida, cordata, insequilaterali, transversira 

 striata ; epidermide viridi, antice posticeque fuscescente ; car- 

 dine angusto ; dentibus lateralibus brevibus. 



Cyrena cyprinodes, Quoy. Sf Gaim. Voy. de VAstrol. Moll. pi. 82. 

 f. 1, 2, 3 (non Gray). 



Hanley, Descr. Cat. p. 93 ; Wood, Ind. Test. Suppl. 2. pi. 14. 

 f.54. 



Hab. In aquis paludosis, stagnantibus, Novae Guine8e(QM03/). 



18. Cyrena divarxcata. B.M. 



C. testa ovato-subcirculari, insequilaterali, tumida, crassa, solida, 

 epidermide fuseo-nigreseente vestita, transversim insequaliter 

 obsolete striata, rugis undulatis, irregularibus, in latere postico 

 divergentibus ; umbonibus obliquis, profunde erosis ; latere 

 antico breviore, superne recto, declivi, in medio attenuato, sub- 

 angulato, latere postico lato, dilatato, obtuse subtruncato ; 

 lamina cardinali lata, plana ; dentibus primariis tribus, inae- 

 qualibus, angustissimis, in valva sinistra duobus latis valde 

 pediculatis, in valva dextra profunde canaliculatis ; dentibus 

 lateralibus minimis, antico conico, acuto, postico oblongo, 

 angusto. 



CjTcna divaricata. Desk. Proc. Zool. Soc. 1854. 



Hab. Nova Guinea. 



19. Cyrena pallida. B.M. 



C testa orbiculato-trigona, magna, solida, in medio convexa, in- 

 aequilaterali, antice posticeque declivi, rectilinea, extremitate 

 posticali attenuata, brevi, truncata, epidermide tenui, luteo- 

 flavescente late striata, vestita ; umbouiJjus parvis obtusis ; 

 area posticali plana, angulo obtusissimo circumscripta ; liga- 

 mento brevi, angusto, partim immerso; valvis solidis, intus 

 candidissimis, cardine angusto tridentato, dentibus angustis, 



