159 



Octooer 22, 1844. 

 Professor Owen, V. P., in the Chair. 



A paper by Sylvanus Hanley, Esq., was read, conteiining descrip- 

 tions of new species of Cyrena, Venus, and Amphidesma. 



"^ Cyrena radiata. Cyr. testd rotundato-cordatd, crassd, solidu, in- 

 eeguilaterali, tumidd,subnitidd, concentrice et subimbricatim siilcatd; 

 epidermide olivaceo-fuscescente, et marginėm convexum aut sub- 

 arcuatum versus, luteo-virescente radiisque nigrescentibus ornatd ; 

 margine dorsali postico declivi, convexiusculo ; lunuld nulld ; nati^ 

 bus acutis, incurvatis, integris ; ligamento parum prominente ; su- 

 perficie internd. purpured ; dentibus lateralibus distinctis, brevibus, 

 minutissime rugulosis (haud crenatis autem), antico approximato. 

 Long. 150; lat. 170 poli. 



Hab. Central America. Mus. Hanley, Cuming, Sowerby. 

 This and the variegata of D'Orbigny are remarkable for being the 

 only radiated Cyrena at present know'n to us. The latter species is 

 decidedly depressed, Avhiist the radiata is peculiarly swollen. 



Cyrena sordida. Cyr. testd suborbiculari, crassd, subinceguilate- 

 rali, ventricosd aut tumidd; epidermide olivaceo-fuscescente et 

 marginėm ventralem convexum versus, luteo-virescente, concentrice 

 rugulosd ; margine dorsali postico, convexiusculo, declivi; natibus 

 erosis, satis prominentibus ; ligamento subin/osso ; lunuld nulld; 

 superficie internd albidd; dentibus lateralibus brevibus obtusis, 

 antico magis approximato. 



Index Tęst. Sup. t. 14. f. 51 . Long, 1-50 ; lat. 1-60 poli. 



Hab. North America. Mus. Hanley. 



The link betvveen Carolinensis and radiata, uniting the interior and 

 membranaceous wrinkles of the former to the general outline of the 

 latter. 



Cyrena Philippinarum. Cyr. testd maximd, compressd, obovatd, 

 valde ineeąuilaterali, ponderosd, antice plicato-sulcatd, epidermide 

 olivaceo-fuscescente, indutd ; margine ventrali convexiusculo ; liga- 

 mentali subdeclivi, et angulum obtusum cum margine postico for- 

 mante ; natibus integris, approximatis, incumbentibus ; ligamento 

 pergrandi, valde prominente ; superficie internd postice et inferne 

 purpured, superne albido-ccerulescente ; dentibus cardinalibus eras- 

 sissimis ; lateralibus supra crenatis aut denticulatis, antico valdi 

 approximato. 



Index Tęst. Sup. t. 14. f. 60. Long. 4 ; lat. 4*75 poli. 



Hab. Philippines. Mus. Cuming, Hanley. 



There are a few narrow diverging folds on the posterior slope, but 

 this character is by no means peculiar to the species, being eąually 



