255 



angustalo, ad apicem rotundato ; latere postico sub-triangulari, 

 rotundato ; margine ventrali valde arcuato, postice sinuato : 

 interior eburnea, incrassata ; dentibus modicis. Long. J ; alt. ^ ; 

 lat. ^ poll. Hob. Singapore. 



The outlines are all gently rounded, and the shell is other- 

 wise characterized by its dead, sallow-white color, and its sculp- 

 ture. 



DoNAX TiNCTUS. Tcsta crassa, ovato-trigona, cuneata, ver- 

 sicolor, scilicet incarnata, straminea vel violacea, striis lamellosis 

 concentricis postice flexuosis insculpta ; umbonibus fere medi- 

 anis ; margine interiori integro; dente laterali valido ; dente 

 antico obsoleto. Long. ^^ ; alt. -^-^ ; lat. | poll. Hob. 



It comes near to D. cuneata^ but is still more like Mesodesma 

 striata in general aspect. The specimens I have examined 

 vary greatly in color, but correspond in form, sculpture, and 

 other characters. 



DoNAX CEOCATUS. Tcsta parva, tenuis, transversa, ovato-tri- 

 angularis, inequilateralis, dilute crocea, concentrice lamelloso- 

 sulcata ; latere antico semi-ovato; latere postico breviori, rotun- 

 dato-truncato ; margine ventrali lente arcuato : intus flavida, 

 nitida ; cardine valido. Long, f ; alt. ^ ; lat. -^^ poll. Hah. 

 Mangsi. 



This small species is sufficiently well characterized, somewhat 

 like D. scalpellum. 



LuciNA RAMULOSA. Tcsta crassa, scabra, lenticularis, vix 

 obliqua, albida, costulis radiantibus crebre divaricantibus et fills 

 continuis concentricis crebris insculpta ; umbonibus elevatis 

 acutis antrorsum versis ; lunula excavata, baud insculpta : ca- 

 vositas albida vel citrina, incrassata ; cicatricibus profundis ; 

 limbo concinne radiato-striato ; cardinis dentibus lateralibus vali- 

 dis. Diam. 1 ; lat. ^ poll. Hah. Paumotu Islands. 



As much allied to L, tigerina or L. interrupta as to any 

 described species, but is more circular, more solid, and the 

 peculiar divergence of the radiating ridges, somewhat like 

 Cytherea divaricata, are sufficiently characteristic. 



LuciNA iNciJLTA. Tcsta tcnuis, lenticularis, retrorsum nonnihil 

 obliqua, stramineo-albida, concentrice striolata ; natibus medianis, 



