CYRENA. 25 



Cyrena cordiformis, RECLUZ, (preoc.) II. Conch. IV, 1853, 251, pi. 

 vii, f. 9. 



The only specimen I have seen of this species, is the one in the 

 cabinet of Mr. Cuming. Mr. Recluz does not assign any locality 

 to it, but I am satisfied on careful inspection that it comes from 

 Central America. Compared with C. inflata, it is heavier, more 

 inflated and more heart-shaped. 



22. Cyrena Climingii, DESHAYES. Shell ovate-subtrigonal, in 

 equilateral, tumid, heart-shaped ; anterior side short, broadly rounded ; 

 posterior side longer, truncated at extremity ; beaks large, prominent, op 

 posite, approximate at apex, eroded ; valves rather solid, interior white ; 

 striae light and irregular ; epidermis brownish-green ; hinge-margin nar 

 row, somewhat broad in the centre ; cardinal teeth approximate, narrow, 

 unequal, bifid ; lateral teeth large, equidistant from the cardinal teeth, 

 anterior tooth larger, conical, acute. 



Long. 2.40 ; Lat. 2.08 ; Diam. 1.76 inches.. 

 &quot; 60; &quot; 52; &quot; 44 mill. 



Hob. Central America. (Cabinet of Cuming.) 



Cyrena cumingii, DESHAYES, Proc. Zool. XXII, 1854, 22. 



A rare shell, the only specimen I have met with is the one in 

 Mr. Cuming s collection. Compared with C. maritima, it differs 

 in having an epidermis, in being larger, transversely more elon 

 gated and less inflated. 



23. Cyrena isocardioides, DESHAYES. Shell orbicular-subtri- 

 gonal, inflated, heart-shaped, light, fragile ; anterior side a regular and 

 broad semicircle ; posterior side forming on the upper part a declivity, 

 subtruncated at extremity ; striae light, irregular ; epidermis olive-color 

 with zones of black; beaks large, curved inwards, opposite, tinted with 

 violet ; hinge-margin very narrow ; cardinal teeth very small, approximate, 

 eubequal, the two anterior ones parallel, the posterior divergent ; lateral 

 teeth small, situated at about the same distance from the cardinal&quot; teeth ; 

 valves white inside, with markings of violet on the margins. 



Long. 2.16 ; Lat. 2.12 ; Diam. 1.60 inches. 

 &quot; 54; 53; &quot; 41 mill. 



Hab. South America, in Western Columbia. (Cabinet of Cuming.) 

 Cyrena isocardioides, DESH. Proc. Zool. XXII, 1854, 22. 



A rare species, the only specimen I have seen is the one in Mr. 



Cuming s collection j it presents great affinity to G. recluzii in 



