813 



Closely resembling the last, of which it is possibly a variety, but 

 is more triangular, and not so distinctly marked with radiating lines. 

 Guiana, Mexico, Florida. 



179. Tellina alba (pi. lxii. f. 193.) Quoy and Gahn., Voy. 

 Astrol. Zool. vol. iii. p. 500. t. 81. f. 1, 2, 3. 



T. testa subovata, solidiuscula, subcompressa, subpellucida, niti- 

 diuscula, extus intusque alba, subla;vigata ; margine ventrali con- 

 vexo et postice sursum acclinato; dorsali antice arcuato et vix 

 subdeclivi, postice elongato declivi et subrecto ; latere antico lato, 

 multum breviore, rotundato ; postico attenuate, obtuse cuneiformi ; 

 ligamento infosso ; costa umbonah et flexura ventrali inconspicuis ; 

 natibus subacutis ; dentibus bifidis, subvalidis, simplicibus subob- 

 soletis. 



Subovate, tolerably strong, rather flat, semi-transparent, nearly 

 smooth, somewhat glossy, white, one of the valves with obsolete 

 concentric stria?; the ventral edge convex and ascending poste- 

 riorly ; anterior side broad, and distinctly the shorter, rounded at 

 its extremity, arcuated and but little sloping at its dorsal margin ; 

 the posterior side obtusely cuneiform, its tip attenuated and ob- 

 tusely angulated, its dorsal edge elongated scarcely convex and 

 obliquely sloping ; beaks rather prominent ; ligament sunken ; 

 umbonal ridge not conspicuous ; the bifid teeth rather strong, the 

 simple nearly rudimentary. 



In all the specimens I have seen, there are two or three obsolete 

 radiating folds at ths anterior extremity. 



Australia. 



180. Tellina peoxima (pi. lxvi. f. 264. and lix. f. 115.) 

 Brown in Zoology to Beechey, p. 154. t. 44. f. 4 ; Phil. Ab. unci 

 Bes. Conch, part 9. pi. 5. f. 4 ; T. sordida, Couthmy, Boston Journ. 

 Nat. Hist. vol. ii. p. 59. t. 3. f. 11 ; Sanguinolaria sordida, Gould, 

 Invert. Massachusetts, p. 67 ; Macroma tenera, Leach, Appendix 

 Ross. Voyage. 



T. testa obovali, tenuiuscula, valde mrequilaterali, convexa, aut 

 convexiuscula, impolita, extus albida, intus Candida, epidermide 

 cinerascente fugaci induta, concentrice obsolete et subimbricatim 

 striolata ; margine ventrali magis minusve convexo ; dorsali antice 

 arcuato et paulo declivi, postice recto et valde declivi ; latere postico 

 brevi, et inferne subangulato ; extremitate postica rotundata ; nati- 

 bus plerumque erosis ; ligamento magno, prominente ; costa um- 

 bonali subobsoleta ; dentium altero in utraque valvula bifurcato. 



Oboval, thinnish, fragile, very inequilateral, more or less con- 



