Zoological Society. 509 



more obtuse hinder extremity, and the greater convexity and less 

 sudden slope of the dorsal edges, suffice for its separation. 



Tellina robust a. Tel. testd parvd, rotundato-subtrigond, solidd, 

 subincequivalvi, subtequilaterali, ventricosd, nitidd, aut albo-flaves- 

 cente, aut pallide rosaced, sublcevigatd (plerumque inferius remote 

 substriatd) ; margine ventrali valde arcuato, dorsali utrinque sub- 

 recto et valde declivi ; latere postico attenuato, fere subrostrato, 

 ad extremitatem acuminato • ligamento angustissimo, infosso ; na- 

 tibus distinctis, protninentibus, et recte incurvatis ; umbonibus 

 tumidis ; flexurd distinctd ; costd umbonali fere obsoletd ; lunuld 

 parvd ; superficie internd, plerumque sub umbonibus, flavidd aut 

 rosed; dentibus ut in T. nuce. Long. 070 ; lat. - 80 poll. 

 Hab. Isle of Annaa, South Seas, and isle of Burias, Philippines ; 

 sandy mud, low water. 



Is closely allied to nux, pinguis and casta, but of a stouter tex- 

 ture even in the youngest individuals. The ligamental edge being 

 nearly straight, easily separates it from pinguis, where it is decidedly 

 convex. 



Tellina casta. Tel. testd obovali, tenuissimd, subincequivalvi, 

 subccquilaterali, pellucidd, convexd, nitidd, extus intusque candidd, 

 leevigatd ; margine ventrali maxime arcuato ; dorsali utrinque sub- 

 recto, subcequaliter satisque declivi ; extremitate posticd angustd, 

 biangulatd; ligamento angustissimo, subinfosso ; natibus acutis ; 

 flexurd ventrali costdque umbonali distinctis; dentibus ut in T. 

 nuce. Long. 036 ; lat. 0'48 poll. 



Hab. Singapore ; sandy mud. 



Bears some resemblance to T. nux, but the shape is less broad, 

 the ventral edge decidedly arcuated, the dorsal edges less convex and 

 shorter, and the umbones colourless. 



Tellina Discus. Tel. testd T. Remiei simillimd, sed subobliqud et 

 sulcis concentricis valde irregularibus, vixque continuis ; natibus 

 hand recte incurvatis ; margine postico dorsali elevatiore, antico 

 dorsali, prope nates prominulas subincurvato ; umbonibus Icevi- 

 gatis ; extremitate posticd angulatd. Long. 2" 75 ; lat. 3 poll. 



Hab. Isle of Mindanao ; on reefs, in coarse sand. 



Tellina cyrenoidea. Tel. testd suborbiculari, solidiusculd, in- 

 cequivalvi, valde inaquilaterali, subventricosd, sordide albd (intus, 

 sub umbonibus, purpurea^), concentrice costellatd ; striis minutis 

 oblique radiantibus, costellas confertas postice decussantibus ; 

 margine ventrali arcuato ; dorsali utrinque valde et subrecte declivi, 

 antice. brevi, postice longiore ; latere antico breviore, obtuse rotun- 

 dato ; extremitate posticd obtusd, paululhm attenuatd; natibus 

 prominentibus ; lunuld distinctd ; ligamento infosso ; flexurd cos- 

 tdque umbonali obsoletissimis ; dentibus lateralibus parvis, distinc- 

 tis, subaquidistantibus. Long. 0*60; lat. 0*70. 



Hab. St. Nicholas, isle of Zebu ; sandy mud, low water. 



In external appearance bears much resemblance to a Cyrena. 



