Mr. Jeffreys on British Mollusca. 33 



has the rostrum much more produced ; the posterior lateral tooth 

 being simple in the right valve of the one, and double in that of the 

 other. Brocchi, in his ' Conchiologia Fossile Subapennina' (p. 515), 

 mentions a specimen which had a primary as well as two lateral 

 teeth. 



Thracia villosiuscula, i. 224. Weymouth (Mr. Thompson). 



T. pubescens, i. 226. Weymouth (Mr. Thompson). 



T. distorta, i. 231. In rock-pools at Arran, N. B., and Bantry 

 (Rev. Mr. Norman). 



Diodonta fragilis, i. 284. Mr. Thompson says he found a live 

 specimen of this local shell at Weymouth in 1855. 



Tellina pygmaea, i. 295. Herm (Rev. Mr. Norman) ; Guernsey 

 (/. G. J.). 



Syndosmya prismatica, i. 321. Guernsey (Rev. Mr. Norman & 

 J.G.J.). 



S. tenuis, i. 323. Guernsey (Mr. Edgar Macculloch) ; Seaford 

 (Rev. Mr. Norman). 



Scrobicularia piperata, i. 326. Weymouth and Southport (Mr. 

 Thompson) ; Hunstanton (Rev. Mr. Norman). 



Erviha castanea, i. 341. Herm (Mr. Macculloch). 



Astarte crebricostata, i. 456, Forbes and Hanley distinguish this 

 from A. sulcata by its having 30 or more ribs, instead of from 20 

 to 30, which the latter species possesses, and by '* the posterior 

 cessation" of these ribs. I have recent specimens from Zetland 

 which show 36 ribs, and others from Norway, which Mr. M*Andrew 

 obtained and obligingly gave me, showing as many as 42 ribs ; but 

 the number of ribs varies much in specimens from diiferent localities, 

 as well as the comparative want or cessation of them on the posterior 

 side, and I must confess that I cannot see more than a varietal dif- 

 ference between the two so-called species. 



A. triangularis, i. 467. Clyde district (Rev. Mr. Norman). 



Cardium. The young of C. echinatum, as well as of C. punctatum 

 and other species, have a remarkable slenderness and obliquity of 

 outline, which in the adult becomes more portly, like 



" the Justice, 

 In fair round belly with good capon lined." 



C. aculeatum, ii. 4. Weymouth (Mr. Thompson). 



C. punctatum. C. nodosum, ii. 22. Clyde district (Rev. Mr. 

 Norman). 



C. pygmseum, ii. 29. Herm and Serk. 



C. papillosum. I found a single valve on the beach at Herm, 

 within a few minutes of my visiting it ; so that it would appear not 

 to be uncommon on that part of our coast. 



Clausina Croulinensis. The largest individual I have of this spe- 

 cies, and which came from the Shetlands, measures in length nearly 

 one-eighth, and in breadth one-tenth, of an inch. In fresh and young 

 specimens a minute spiculum or horn-like process is seen to project 

 from the right beak in a line with the shell. I should not be sur- 

 prised if it proved to be the young of the Axinus Sarsii of Loven, 



Ann. b; Mag. N. Hist. Ser. 3. Fo/.iii. 3 



