258 BIVALVE SHELLS. 



satis solida, transversim insequaliter tenuissime striata, epider- 

 mide fusco-virescente, itiferne lamellosa vestita; lunbonibus 

 magnis, j)roniinentibus, ojjpositis, decorticatis, approximatis, 

 latere antico brevi, late rotundato, postico attenuate, superne 

 declivi, extremitate truncato, angulo obtuso deciirrente cir- 

 cumscripto ; cardine angusto, in medio paulo latiore ; dentibus 

 tribus primariis in:cqualibus ap])roximatis angustis, apice pro- 

 funde bifidis, lateralibus magnis ffiquidistantibus, antico joaulo 

 majore, conico, acuto ; valvis intus candidissimis. 

 CjTena (anomala) Cumingii, Desk. Proc. Zool. Soc. 1854. 

 Hab. America centralis. Coll. Cuming. 



62. Cyrena Isocardioides. 



C. testa orbiculato-subtrigona, inaquilaterali, turgida, cordiformi, 

 tenui, fragili, tenuissime transversim inaequaliter striata, epi- 

 dermide olivaceo-nigrozonulata, vestita ; umbonibus magnis, 

 subinvolutis, oppositis, atro-violaceis ; latere antico regulariter 

 late semicirculari, postico superne declivi, attenuate, subros- 

 trato ; area plana, ovato-lanceolata, angulo lato obtuso de- 

 currente circumscripta; cardine angustissimo, dentibus pri- 

 mariis tribus minutissirais, approximatis, suba;qualibus, duobus 

 anticis parallelis, postico divaricate ; dentibus lateralibus mini- 

 mis, subaequidistantibus, margine sulco angusto profundo 

 separatis, in valva dextra duplicatis ; pallii impressione margine 

 inferiore proxima ; valvis intus albis, utroque latere violaceo 

 maculatis. 



Cyrena (anomala) Isocardioides, Desk. Proc. Zool. Soc. 1854. 



Hab. Columbia occidentalis. Coll. Cuming. 



53. Cyrena maritima. 



C. testa orbiculato-cordiformi, subgequilaterali, turgida, tenui, 

 transversim irregulariter et dense striata, epidennide viridi- 

 fuscescente induta; umbonibus magnis, parum obliquis, ap- 

 proximatis, acutis, laevigatis, latere antico superne declivi, 

 convexiusculo, in medio parumper attenuate et obtuso, postico 

 breve truncato; area magna cenvexa, evata, angulo obtuso 

 decurrente circumdata ; cardine angusto ; dentibus primariis 

 tribus, minimis, suba^qualibus approximatis, apice bifidis diver- 

 gentibus, lateralibus acqualiter remotis, in valva dextra du- 

 plicatis, antico usque ad cardinem canaliculate. 



Cyrena maritima, Adams, Panama Shells. 



CjTena (anomala) maritima. Desk. Proc. Zool. Soc. 1854. 



Hab. Panama. Coll. Cuming. 



