285 

 CHEIRURUS MERCURIUS. (N. sp.) 



Fig. 272. 



Description. Glabella obtusely conical, convex, front half tumid, sides 

 straight or gently convex, sub-parallel, front broadly rounded. Neck 

 furrow extending all across; posterior pair of glabellar furrows nearly 

 straight and sub-parallel with the neck furrow, extending all across, but 

 the middle third not so deeply indented ; the two anterior pairs are short 

 and obscurely marked. 



The eye appears to be small, close to the side of the glabella, and just 

 opposite the end of the posterior glabellar furrow. The cheeks seem to 

 have the form of 0. Vulcanus. 



Associated with this species are some specimens only differing by having 

 the last pair of glabellar furrows not connected in the middle. 



Locality and Formation. P, Cow Head, Newfoundland : Quebec 

 group. 



Collector. J. Richardson. 



CHEIRURUS PROLIFICUS. (N. sp.) 



Fig. 272. Fig. 273. 



Fig. 272. Cheirurus Mercurius. Upper and side views of the glabella. 

 273. C. prolificus. Upper and side views of the head. 



Description. Head short, convex, about quarter of a sphere ; cheeks 

 triangular, drooping, rounded at the angles ; glabella conical, narrowly 

 rounded in front, sides gently convex, neck furrow extending all across, 

 three pairs of glabellar furrows, the last with the inner extremities separated 

 by a little less than one-third the width, the others a little shorter, all 

 slightly curved, the convex side forwards. The eyes are small and 

 opposite the second lobe from the neck furrow, and a little nearer the side 

 of the glabella than to the centre of the cheek. The posterior and outer 

 cheek margins have a narrow elevated rim. Surface of cheeks and 

 glabella finely tuberculated. 



Width of an average sized head 6 lines ; length 4 lines. 



This species is closely allied to both O. Vulcanus and O. Mercurius, and 

 occurs in great numbers in the same fragments of limestone with them. 



