239 



narrower thoracic rings, and the smooth and obscure axis of the pygi- 

 dium. 



This form might be referred to Niobe, but for the obscurity of the 

 glabella (and the almost entire absence of rachis to the pygidium, if we 

 are right in referring the smooth pygidium to this head and thorax). 

 This form cannot belong to Platypeltis, Cal., because it has eight seg. 

 ments, and no frontal enlargement, of the glabella is traceable ; on the 

 contrary, the glabella is conical ly rounded, as in Asaphus. 



CTENICHNITES BISULCATUS, n. sp. 



This track I have not seen elswhere in the Cambrian rocks. The fur- Ctenichnites 

 rows are arched like those of C. ingens, but only two furrows are found 

 together and these a little over two inches apart. The impression of the 

 outer one fourteen inches or more in length, was much stronger than 

 the inner ; the latter was visible for a length of only three inches ; the 

 outer track is more strongly arched at the ends than elsewhere ; the 

 chord of the arch is about half an inch from the highest part of the arch. 



Horizon and locality. On a flag of the Johannian Division. (C. 2a.) 

 Falls of MacMullin brook, Indian brook, Escasonie N.S. 



