287 

 CHEIRURUS PERFORATOR. (N. sp.) 



Fig. 275. 



Fig. 275. Cheirurus perforator. The front half of the glabella with portions of the 



fixed cheeks. 



Description. Large, glabella strongly elevated in front, obtusely conical 

 with deep linear furrows, and a long cylindrical rostrum. Cheeks coarsely 

 punctured, and glabella with a few rounded tubercles. 



The only specimen of this remarkable trilobite discovered, is the 

 anterior part of the glabella, with a small portion of the cheek on each 

 side. The length, from the base of the rostrum, backwards as far as 

 preserved, is 9| lines, measured along the median line of the upper side. 

 At 5 lines from the base of the rostrum there is a pair of deep linear 

 glabellar furrows, very gently curved (the convexity forward), their upper 

 extremities distant from each other about 3 lines, the lower extremity 

 about 1 line from the cheek, and 7 lines from the base of the rostrum ; 

 length of each furrow 5 lines. About 3 lines behind there is a second 

 furrow not so much curved which extends to the cheek below, and appears 

 to run all across (but this point is not determined owing to the imperfec- 

 tion of the specimen). It seems probable that if this specimen were perfect, 

 the total length of the glabella would be from 12 to 15 lines, and there 

 may be, thus, another pair of furrows besides the neck furrow. 



I at first supposed this remarkable fossil to be an Ampyx, and had so 

 described, but fortunately, before printing, other species of the same 

 type were discovered, which shew that it is a Cheirurus with the unusual 

 appendage of a large spine on the head. 



Locality and Formation. N, Table Head, Newfoundland ; Quebec 

 group. 



Collector. J. RicSardson. 



