BIVALVE SHELLS. /1 



50. DlONE GIBBOSULA. 



D. testa rotundato-trigona, obliqua, inaequilaterali, convexiuscula, 

 antice brevi, obtusa, inferne convexa, superne arcuato-gibbosa, 

 postice subangulata, alba, postice fusco-caerulescente vel radi- 

 ata vel pallide violacea, lateribus et apicibus longitudinaliter 

 costatis, rugis transversalibus undulatis decussatis et crenu- 

 latis ; in latere postico costis pluribus majoribus, alteris tenue 

 granulosis ; lunula nulla ; area plana, laevigata ; valvis intus 

 albis, impressionibus muscularibus violaceis ; sinu pallii hori- 

 zontali, trigono, acuto, subaequilaterali. 



Chione gibbosula, Desh. Proc. Zool. Soc. 1853. 



Hab. ? Coll. Cuming. 



51. DlONE COR. 



D. testa cordato-trigona, intus extusque alba, convexiuscula, un- 

 dique concentrice striata; striis exilibus, regularibus, confer- 

 tissimis ; latere postico majore, subcuneiformi ; margine Hga- 

 mentali valde declivi, convexiusculo ; ventraH subarcuato ; 

 natibus acutis ; lunula oblonga, impressa ; margine intemo 

 integro. 



Cytherea cor, Wood, Ind. Test. Suppl. pl. 15. f. /• 

 Hanley, Proc. Zool. Soc. 1844, p. 110. 



Hab. Africa. 



52. DlONE CONVEXA. 



D. testa ovali, ventricosa, fulva, irregulariter striata ; latere antico 

 brevi, attenuato, subrostrato, postico obtuso, aetate subtruncato ; 

 lunula lata, plana, cordiformi ; sinu palhi brevi, trigono, apice 

 acuto. 



Cytherea convexa, Say, Journ.Acad.Nat. Sci. Phil. iv. pl. 12.f.3. 



Catlow, Conch. Nom. p. 87. no. 23. 

 Cytherea Savana, Conrad, Sill. Journ. xxhi. 345. 



Sow. Thes. Conch. p. 638. pl. 132. f. 119. 



Hanley, Descr. Cot. p. 105 ; in Wood, Suppl. pl. 15. f. 34. 



Dekay, Zool. de New York, v. 216. pl. 2?. f. 279. 



Hab. Status Uniti Americae septentrionahs. 



53. DlONE ROSTRATA. 



D. testa cordata, tumida, albida, striata, opaca ; apicibus valde 

 revolutis ; lunula maxima, cordata, planiuscula, area nuUa. 



Cytherea rostrata, Koch in Phil. Abbild. Conch. p. 150. pl. 1. f. 3. 



