323 



Length of the head 3 J lines ; -width of the same 5 lines ; width of the 

 glabella, 2i lines. 



The glabella of A. Westoni is nearly flat, and the eye situated not so 

 far forward as it is in this species. 



Locality and Formation. Stanbridge, range 6, lot 20 ; Quebec group. 



Collectors. J. Kichardson, T. C. Weston. 



CHEIRURUS GLAUCUS. (N. sp.) 



Fig. 308. Fig. 309. 



Fig. 308. Cheirurus Glaucus. a, side view of the glabella ; 6, upper side of the same 

 with part of the cheeks. As this view is a vertical one, the spine seems 

 to be further back than it is in a. 

 309. C. Satyrus. Side view of the glabella, enlarged two diameters. 



Description. Head strongly convex with a small cylindrical spine just 

 behind the centre of the upper surface of the glabella. Glabella obtusely 

 conical ; sides gently convex, a little converging forwards ; front margin 

 broadly rounded ; neck furrow all across ; three pairs of glabellar furrows ; 

 the first pair curving backwards and inwards, making the posterior lobes 

 about one-third the length of the glabella from the neck furrow to the 

 front margin, and one-third the width ; the second pair at about the mid- 

 length, and the third a little in advance of the second. These two pairs 

 of furrows extend about half way up the sides, and have the convex curve 

 forwards. On a side view 7 , the outline is strongly arched upwards to the 

 mid-length, just behind which rises the spine, from the base of which to 

 the neck furrow there is a straight slope. The front of the glabella 

 appears to be bordered by a very narrow rim. The surface of the 

 glabella seems to be smooth. 



This species is allied to C. perforator, (ante, p. 287,) but differs in 

 having the spine not so far forwards. C. Satyrus has a much larger 

 spine. 



Locality and Formation. Stanbridge, range 6, lot 20 ; Quebec group. 



Collector. -T. C. Weston. 



