397 

 AGNOSTUS ORION. (N. sp.) 



Fig. 373. 



Description. Length and breadth about equal, sub-circular, convex, a 

 very narrow margin all round, glabella not quite two thirds the whole length 

 very convex, a transverse furrow at one third the length from the apex, a 

 small triangular tubercle at each side next the posterior edge ; no tubercle 

 visible on the top of the glabella. A fissure from the apex of the glabella 

 to the anterior margin. Length two lines. 



This species only differs from A pisiformis as figured by Salter in the 

 3rd Edition of Siluria by having the glabella proportionally shorter. 



Limestone, No. 1. In No. 2 there are two specimens of an Agnostus 

 which resemble this species, but more are required to decide whether they 

 are identical or not. 



AGNOSTUS CANADENSIS. (N. sp.) 



Fig. 374, o. b. 



Description. Head, obtusely oblong, semi-oval ; width, a little greater 

 than the length ; a concave border nearly as wide as the glabella all round. 

 Glabella in width, less than half the width of the head, and in length a little 

 more than two-thirds the length of the head : a triangular tubercle on 

 each side of the neck, and a transverse furrow a little in advance of the 

 mid-length ; the tubercle is obscure, and appears to be indicated by the 

 small indentation forward in the middle of the transverse furrow. 



The specimen represented by Fig. 374 a, is provided with a tubercle, but 

 I cannot see in which direction the apex is directed, and consequently am 

 unable to say whether it is a head or a tail. It has the broad margin of 

 Fig. 374 6, and I think therefore it belongs to the same species. The seg- 

 ment next the thoracic extremity is a little less than one-third the whole 

 length, and about one-third the whole width. The posterior segment is large 

 and convex, extending quite to the concave border, where it is full one-half 

 wider than it is at the suture between it and the smaller segment. The tu- 

 bercle is situated in the transverse suture, and makes a small indentation 

 in the edge of the larger segment. 



Length of the specimens, about two lines. 



Limestone, No. 1. 



