GONCRYUA—DITHYRA. 31. 12§ 



Tellina crassa. Lister, Conch, tab. 376, fig. 218. 

 Mus. nost. Dawlish and Teignmouth sands, generally single valves : 

 fine and perfect from Guernsea. 



Shell about half an inch long, and nearly an inch broa^, whitish 

 with purple rays, much thicker and more abrupt at the broader end 

 than the Donax Trunculus ; and may be known by the punctures in 

 the interstices of the longitudinal striae, and the rough ridges on 

 the truncated slope, which is elevated in the middle into a kind of 

 keel : inside white, with a lateral tooth on each side the primary ones. 



** Margins interno integerrimo. 3-5 

 With the inner margin very entire. 



Donax testa ovato-oblongd Iwvi, vittd alba longitudinali, dentibus <="™P^a"a'"- 



lateralibus in utrdque valvd. 

 Shell oval oblong smooth, with a single white longitudinal band, and 

 lateral teeth in both valves. 



Tab nost. 7, fig. 13, 14. 

 Donax complanata. Montagu, p. 106, tab. 5, fig. 4. 

 Linn. Trans, viii. p. 75. 

 Turton, British Fauna, p. 156. 

 Pennant, Brit. Zool. iv. p. 198. 

 Dorset Catal. p. 34. 

 Dillwyn, Descript. Catal. p. 150. 

 Turton, Conch. Diet. p. 42. 

 Pectunculus tenuis. Lister, Conch, tab. 384, fig. 227. 

 Mus. nost. Torbay, and Guernsea. 



