325 



arch is depressed in the upper part, as in figure 310, a ; while some (jr) 

 have the posterior part arising abruptly from the neck fiirrow, and so 

 extremely convex as to exhibit a tendency to become prolonged into a 

 spine. There is a regular gradation between these forms, and they seem, 

 therefore, to be all of one species. 



The specimens above figured were collected in Stanbridge, range 6, lot 

 20 ; Quebec group ; by T. C. Weston. 



CHEIRURUS PROLIFICUS (ante, p. 285). 



Fig. 311. Fig. 312. 



Fig. 311. Cheirurus proliftcus, Glabella from the Township of Stanbridge. 

 312. -'A specimen from the Chazy limestone, Montreal. 



Remarks. This species occurs at Stanbridge along with 0. Vulcanus. 

 Fig. 312 is drawn from a gutta percha cast of the impression of the gla- 

 'bella of a Cheirurus, in a piece of Chazy limestone. It exhibits only two 

 pairs of glabellar furrows, but it is evident that the whole of the glabella 

 Is not represented in the cast, and it is almost certain that there is a third 

 pair. It is either (7. prolificus, or a very closely allied species. 



REMOPLEURIDES AFFINIS. (N. sp.) 



Fig. 313. 

 Fig. 313. Remopleurides affinis. Glabella enlarged two diameters. 



Description. Glabella rather strongly convex ; width between the 

 eyes a little less than the whole length ; front abruptly elevated ; width 

 of the neck segment and also of the portion of the glabella in front of the 

 eyes a little more than half the width between the eyes. The eyes are 

 semi-annular, a little more than half the length of the glabella and neck 



