26 CANADIAN FOSSILS. 



Euomphalus granulatus and E. lineatus, Portlock, Turbo crebristria, 

 McCoy*, and T. sulcifer of Eichwald, in addition to those described 

 by Hall, will certainly fall into it. These, with numerous concentric 

 ribs, none of which are specially prominent, lead the way easily to 

 such forms as T. rupestris, Eichwald, in which most of the ridges are 

 suppressed, and a few large ones only remain. The bands of color 

 follow the direction of the ridges in the last named elegant species. 



T.trimarginatus, Eichwald, is another similar form. It is difficult, 

 if not impossible, to draw the line between such species as these and 

 the several gradations which lead back to C. bilix or the fossil here 

 figured. The group appears to range into the Devonian rocks, as 

 we learn from the figures of the MM. Sandberger of Nassau. 



C. Halliana, N. sp. 

 Plate VI. Figure 1. 



C. turbinata, ventricosa, anfractibus 5 rotundatis, supra paullulum plana- 

 tis, — ultimo ad basin gibboso, striis que concentricis undulalis cincto ; 

 basi subangulatd lavi; ore rotundo. 



It is not difficult to distinguish this from the C- bilix ( Plcurotomaria 

 bilix, Conrad), for the whorls are much rounder and the spire conse- 

 quently not nearly so conical ; the striae only cover a part of the 

 whorl, and the pillar-lip is not so straight or so much reflected. 

 The species are however very closely allied. 



The whorls are rounded, and even rather gibbous toward the lower 

 part, but there is a decided flattening above, and the base too is a 

 little flattened (not nearly so much as in C. bilix). The lines of 

 growth are oblique backwards, as far as the basal angle, if it may 

 be so termed, and thence turn forward, making a slight sinus. 

 [This character is even more decided in the C. bilix, and is greatly 

 exaggerated in the genus Eunema.'] 



The suture is well pronounced, the upper part of the whorl free 

 from concentric striae, which occur only on the sides ; the base also 

 is smooth. The mouth is roundish, a little prominent only beneath 

 the columellar lip, which is not quite vertical, nor is the inner lip 

 much reflected or more than slightly concave. 



Locality. — Pauquette's Rapids. 



* Palaeozoic Fossils, Woodwardian Museum, Cambridge, Plate 1 L, figure 22. 



