VENUS. 423 



the term lamellre), which gird the entire exterior, become 

 very closely disposed near the lower margin, but are much 

 more distant towards the beaks. These strise are ra- 

 diatingly decussated by elevated and crowded lines, which 

 appear more or less distinctly to traverse them, and not to 

 be confined to their interstices. 



The ventral margin is arcuated, and rises considerably at 

 both extremities. The declination of both dorsal edges is 

 likewise considerable ; the front one is incurved, somewhat 

 abrupt, and rather longer than is usual in the genus ; the 

 hinder, which is of moderate length, slopes with but little 

 convexity, except near the prominent beaks (which are very 

 acute and curve peculiarly forward), to the ventral margin, 

 with which it forms a rather narrow subangulation. The 

 front extremity is narrow, well rounded below, but less 

 distinctly so above. The lunule is large, elongated-cordate, 

 and profoundly impressed ; the hinder dorsal area is rather 

 broad, flattened, and a little retuse : the ligament, though 

 not prominent, is very distinct. The dentition is that of 

 striatula. 



The length of the individual we have been describing is 

 full eleven lines ; its breadth is four-fifths of an inch. 



SPURIOUS. 



Vemis sulcordaia, Mont. Test. Brit. p. 121, pi. 3, f. 1. — Linn. Trans, vol. viii. 

 p. 82.— TuRT. Conch. Diction, p. 237 ; Dithyra Brit. p. 145. 

 — Flem. Brit. Anim. p. 447. — Brit. Marine Conch, p. 87. — 

 Index Testaceol. pi. 7, f. 16. — Dillw. Recent Shells, vol. i, 

 p. 166. 



Although we regard the V. suhcordata of Montagu, whose 

 type is still preserved in our National Museum, as only the im- 

 mature state of the V. radiata of Chemnitz (Conch. Cab. vol. 

 vi. p. 371, pi. 36. f. 386.— Dillw. Recent Shells, vol. i. p. 189), 

 we have preferred drawing up our description from that stage, as, 



