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Iphidea BELLA. (N. gen. and sp.) 



FiG. 44. i/>A«£fea i^^^a; ventral ? aspect. 



Of this genus we have no specimens showing the internal structure^ 

 but the external characters seem sufficient to separate it from any 

 described generic group. The ventral ?. valve of I. bella, is conical, 

 strongly elevated at the beak, hinge-line nearly straight, posterior angles 

 narrowly rounded, sides and front nearly uniformly rounded, forming 

 rather more than a semi-circle. Posterior side with a large false area, 

 and a convex pseudo-deltidium, the width of which at the hinge-line is 

 nearly one-third the whole width of the shell. The dorsal valve is semi- 

 circular, moderately convex, most elevated at the beak. The hinge-line 

 appears to be straight. The form and structure of the posterior 

 side, (such as the area, foramen, deltidium, &c.,) cannot be made 

 out from the specimen, owing to its imperfection. The surface is 

 covered with fine concentric striae, which in the ventral ? valve are 

 continued around on the area. Of these strioe there appear to be from 

 fifteen to twenty in the width of one line, their size varying somewhat in 

 different parts of the specimen. There are also a few obscure radiating 

 striae. Width of ventral valve, seven lines; length, five lines; height, 

 two lines. 



In the specimen above figured there is an aperture in the beak, but in 

 another there is no appearance whatever of a perforation. This genus 

 resembles Acrotreta, but differs therefrom in having a large convex delti- 

 dium. It seems to be also closely allied to Kiitorgina. The shell which 

 I have described under the name of Oholus Lahradoricus belongs to this 

 genus. 



J. hdla was found by T. C. Weston, in a boulder of limestone associ- 

 ated with numerous fragmentary trilobites, of primordial age, near Trois 

 Pistoles below Quebec. A closely allied species of the same genus occurs 

 in the primordial limestone at Topsail Head, Conception Bay, Newfound- 

 land. 



FOSSILS IN THE HURONIAN ROCKS. 



AspiDELLA Terranovica. (N- gen. and sp.) 



These are small ovate fossils five or six lines in length and about one- 

 fourth less in width. They have a narrow ring-like border, within which 



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