CYRENA. 



13 



2. Cyrena sordida, Hanley.— C. testa suborbicuLari, crassa, sub- 

 inaequilaterali, veutricosa aut tumida ; epidermide olivaceo-fucesceute et 

 marginem ventralem couvexum versus, luteo-viresceute, concentrice rugu- 

 losa ; margine dorsali postico, convexiusculo, declivi ; uatibus erosis, satis 

 prominentibus ; ligameiito subiufosso ; lunula nulla; superficie interne 

 albida ; dentibus lateralibus brevibus obtusis, antico magis approximato. 

 Long. l.GO; Lat. 1.50 inches. 



Hah, Central America. (Cabinet of Hanley.) 



Cyrena sordida, Hanley, Proc. Zool. XII, 1844, 159. — Index Test. 

 Siippl. pi. xiv, f. 51. 



I have not been able to identify this species. "The link be- 

 tween C. caroliniensU and C. radiala, uniting the interior and 

 membranaceous wrinkles of the former to the general outline of 

 the latter." — Hanley. 



Fig. 7. 



3. Cyrena radiata, Hanley. — Shell rounded, somewhat oblique, 

 heart-shaped, thick, solid, inequila- 

 teral, tumid, anterior side broad, 

 rounded, posterior somewhat more 

 extended, abrupt at extremity ; 

 beaks small, acute, approximate at 

 apex, entire ; striae regular, epider- 

 mis light olive-green, shiny; interior 

 of the valves violet ; hinge-margin 

 very much curved, thick ; cardinal 

 teeth unequal, divergent, the poste- 

 rior teeth bifid at summit ; lateral 

 teeth unequal, the anterior tooth ai> 

 proximate, the posterior tooth elon- 

 gated ; sinus broad at mouth, acute 

 at extremity, very short. 



Long. 1.40; Lat. 1.20, Diam. 1.00 inch. 

 42; " 39; " 28 mill. 



Hah. In Central America, at Realejo, Nicaragua. (Cabinets of Hanley, 

 the British Museum, Smithsonian Institution, Sowerby, Jay and Prime.) 



Ci/rcna radiata, Hanley, Proc. Zool. XII, 1844, 159. 



The specimens from which this description was prepared were 

 identified for me by the author himself. In some cases the epider- 

 mis of this species shows rays of a darker hue running from the 

 beaks to the basal margin, this feature is, how^ever, rather the ex- 

 ception than the rule. Compared with C. arctata, to which it 



C. radiata. 



