116 COl^CHYUk—niTHYRA. 28. 



Shell more than an inch in diameter, very thin and brittle, 

 yellowish white, irregularly striate transversely, a little undulate 

 in the circumference: beaks nearly central, without impression 

 under them, inside glossy yellowish-white : hinge with three teeth 

 in one valve, the middle one cloven. 



Radiiia. LuciNA testd lentiformx, strils transversis crehris laminatis, 

 valvis bidentatis. 

 Shell lenticular, with close-set transverse laminar striae, and two 



teeth in each valve. 

 Tellina Radula. Montagu, Test. Brit. p. 68, tab. 2, fig. 1, 2. 

 Linn. Trans, viii. p. 54. 

 Pennant, Brit. Zool. iv. p. 181. 

 Turton, British Fauna, p. 151. 

 Wood, Conch, p. 183, tab. 42, fig. 4, 5. 

 Turton, Conch. Diet. p. 175. 

 Venus borealis. Donovan, British Shells, iv. tab. 130. 

 Venus spuria. Dillwyn, Descript. Catal. p. 194. 

 Cognata Veneris Pensylvanicae. Chemnitz, vii. p. 16, tab. 38, 



fig. 399. 

 Pectunculus subfuscus. Lister, Conch, tab. 293, fig. 129. 

 Mus. nost. Western and Irish coasts. 



Shell an inch and a half in diameter, rather convex, running 

 in a nearly straight line on each side the beaks, giving that 

 end of the shell a rather truncated appearace, white or co- 

 vered with a pale brown skin, and marked with numerous 

 rough raised concentric ridges; inside dull chalky white, 

 except round the area of the margin, which is polished and 

 furnished with longitudinal lines, as in many species of this 



