﻿BIVALVIA. 



135 



reference he is probably correct, and I have, therefore, had figured one of my small 

 specimens which seems to correspond with the nodosum of Turton. The recent shells 

 called nodosum and fasciatum being kept separate by conchologists, I have here, in defer- 

 ence, done the same, although, I confess, not without misgivings. Dr. Loven (' Ind. 

 Moll. Scandin.,' p. 35), when describing C. fasciatum and others, says, " Cardia Europaea 

 misere confusa," and I feel disposed to echo his words. 



Mr. Jeffreys, in his list to Mr. Prestwich's paper (p. 138), introduces C. Norvegicum 

 as a new Cor. Crag species, but no locality is attached to the name ; and in his list of 

 Red Crag shells in the same paper (p. 482) Card, interruptum is referred to this species 

 (viz. C. Norvegicum). If this be the form upon which the name Norvegicum is thus 

 introduced as a Coralline Crag species, it will not require another figure; but I have not 

 yet been able to see a shell like C. interruptum from the Coralline Crag, or to refer any of 

 my specimens satisfactorily to C. Norvegicum. 



Cardium Parkinsoni, /. Sow. Crag Moll., vol. ii, p. 158, Tab. XIII, fig. 7. 

 Localities. Red Crag, Walton, Sutton, and Butley. 



This species is exceedingly abundant at Walton, but rare in other parts of the Red 

 Crag. Dr. Woodward, in his list in ' White's Directory/ gives it (in fragments) from the 

 Pluvio-marine Crag of Thorpe-by-Norwich, but I have not seen the shell from that Crag, 

 and suspect that the fragments referred to are those of the large individuals of edule so 

 common in the Norwich Crag and Lower Glacial sands. Parkinsoni much resembles 

 C. Nuttalii, Conrad, a shell living in the seas of Upper California ( e Journ. Nat. Hist. 

 Soc. Boston,' vol. vii), but I believe our Crag shell to be distinct, as it is less oblique, 

 with fewer and broader ribs, and these are united at their bases, while the ribs in 

 Nuttalii have a distinct space between them. In both species the ribs are imbricated. 



Cardium decorticatum, S. Wood. Crag Moll., vol. ii, p. 159, Tab. XIV, fig. 1. 

 Localities. Cor. Crag passim. 



This is abundant in a fragmentary state in the Cor. Crag, but perfect specimens are 

 difficult to obtain ; it was a handsome shell, and fragments indicate a length of 3^ inches. 

 C. venustum resembles it, and may possibly be the same species ; but, as I have before 

 stated, it is a smaller shell and smoother, the ribs in decorticatum being prominent and 

 distinct. In the list annexed to Mr. Prestwich's Cor. Crag paper this shell is referred to 

 C. lavigatum, Poli, but in the list to the Red Crag paper it is referred to C. Norvegicum. 

 I cannot, however, agree in either reference ; and have not seen it from the Red Crag, 

 but only the allied form venustum. 



