408 



bella is separated from the cheeks and front margin by the deep, narrow 

 dorsal furrow which runs all round. The eyes are situated opposite the 

 anterior glabellar furrows, and distant from the glabella about one-fourth 

 the width of the neck segment. The front margin slopes from the front of 

 the glabella downwards, and is then turned up to form a slightly elevated 

 but well denned wire-like rim, which probably runs all round. Surface 

 covered with small tubercles. Cheeks, thorax and pygidium unknown. 

 Length of largest specimen collected, four lines ; length of glabella, in- 

 cluding neck segment, three lines ; width of, at neck furrow, two lines. 



In some specimens a third glabellar furrow is represented by an obscure 

 indentation close to the front. 



The facial suture is evidently the same as in A. cylindricus and A. sub- 

 davatus. 



Limestone, No. 1. 



MENOCEPHALUS GLOBOSUS. (N. sp.) 



Fig. 388 a, b, c. 

 * 



Description. Head globose, the posterior angles produced into small 

 slender spines directed outwards, at an angle of about 45 with the axis 

 of the body. Glabella exceedingly convex, almost hemispherical, its 

 length slightly exceeding its width ; either totally destitute of lateral fur- 

 rows, or with two inconspicuous indentations on each side. Neck furrow 

 and segment well defined ; the margin of the head with a narrow, wire- 

 like border all round, which turns up in front of the glabella, and forms an 

 obtusely pointed rostrum ; cheeks moderately tumid, but drooping on each 

 side, so as to give a great depth to the outline of the head. Eyes about 

 one-fifth the total length of the head, situated opposite the mid-length of 

 the glabella, and about their own width from it. Facial suture as in A. 

 subdavatus. Surface covered with small tubercles. Width of head in 

 the specimen figured, five lines; length, three lines ; length of glabella, 

 two lines and one-fourth. 



Associated with these are very numerous glabellse of a larger size, in 

 general four lines in length, which probably belong to this species. 



Limestone, No. 1. 



G-enus BATHYURTJS. Billings. 



This genus was described in the " Canadian Naturalist and Geologist," 

 vol. iv, p. 364, in the article on the fossils of the Calciferous Sandrock. 

 It differs from Asaphus by having nine segments in the thorax, the front 



