110 



Minute ta\vny zigzags adom the Avhitish ground of tlie anterior sur- 

 face, whilst the fulvous hue predominates posteriorly. 



Cytherea Philippinarum. c. testd cordatd, incequilateraU, ven- 

 tricosd, crassiusctild, pallide lividd, radiis et lineis angulntim 

 fiexuosis saturatioribus variegatd, concentrice costellatd ; costellis 

 convexis, confertis ; interstitiis lavigatis ; lunuld hrevi, cordiformi, 

 albd; rimd livido purpurascente ; margine ventrali iniegro, arcuato ; 

 superficie internd albidd, macvld lividd sub umbonibus notatd. 

 Long. 0-80; lat. 1 poli. 

 Index Tęst. Sup. t. 15. f. 3B. 

 Hab. Philippines. Mus. Cuming, Hanley. 



Veiy distinctly characterized by its crowded naiTO\v ribs. The 

 dentition is that of its subgenus Chione, and the short white lunule, 

 equally ■with the narrow ligament, is bordered with livid purple. 



Cytherea Diemenensis. C. testd oblongo-cordatd, convexd, nitidi- 

 usculd, concentrice et obsolete sulcatd, carneo-fulvd ; radiis angustis 

 hinuldgue lanceolatd, colore tinctis saturatiore ; pube albd, strigis 

 flexxiosis litterutd ; sitperficie internd albidd, radio fusco-purpureo 

 obliquo, sub ttmbonibus ornatd; margine integro. Long. 0"80 ; 

 lat. 1-20 poli. 

 Hab. Van Diemen's Land. Mus. Metcalfe. 

 Easily to be distinguished from those allied to it in form by its 

 internal vay. The hinge is that of the section Chione. 



Cytherea cok. C. testd cordato-trigond, intus extusque albd, con- 

 vexiusculd, undique concentrice striatd ; striis exilibus, regitlaribus, 

 confertissimis ; latere postico majore, subcuneiformi ; margine 

 ligamentali valde declivi, convexiusculo ; ventrali subarcuato ; nati- 

 bus acutis; lunuld oblongd, impressd; margine interno integro. 

 Long. 0-80; lat. 1 poli. 



IndexTest. Sup. t. 15. f. 7. 



Hab. Africa. Mus. Metcalfe. 



Not unlike the Venus va7-iabilis of Sowerby in shape and general 

 appearance. The epidermis is of that \vhite velvety texture which 

 we meet M'ith in argentea. 



Cytherea Hindsii. C. testd trigond, ventricosd, solidiusculd, la- 

 vigatd, nitidd, subaquilaterali, albidd, brunneo nebulosd, utrinque 

 obtusd ; latere antico paululiim majore ; natibvs incurvatis, pallidis ; 

 lunuld mugnd, subinconspicud, omnino pallidd ; pube fusco stri- 

 gatd; sujierficie internd albidd; margine integro. Long. 1 ; lat. 

 1 poli. 



Index Tęst. Sup. t. 15. f. 35. 



Hab. Guayaquil. Mus. Cuming, Hanley. 



This and the succeeding species belong to the subgenus Trigona, 

 and are easily distinguished from the Mactroides of Born and Chem- 

 nitz by the abseuce of a purple stain upon the umbones. 



" Descriptions of ne\v species of Tritons, collected chiefly by H. 

 Cuming, Esq. in the Philippine Islands," by Loveli Reeve, Esq. 



Tritojt gallinago. Trit. testd abbreviato-clavceformi, varicibus 



