Description of a new Trilobite, 423 



gical range of the genus on this side of the Atlantic. In Europe 

 ConocepTialites has not been found out of the primordial zone of 

 Barrande, but the Quebec and Keeseville specimens show that 

 here it reaches the Lower Sikirian. 

 Montreal, July 22nd, 1860. 



*• (Additional note in Silliman^s Journal^ Nov. 1860.) 



Since my note to Mr. Bradley's paper was written, he has col- 

 lected quite a number of new specimens of C. minutus at the 

 same locality. At his request I have examined them and find 

 that they exhibit several of the parts not preserved in those upon 

 which the original description was found. 



Fig. 4. — a, A detached cheek showing the small spine of the posterior 

 angle. 

 6, c, Two specimens of the glabella, showing the spine on 

 the neck segment. 



1. The posterior angles of the head are produced into short 

 spines, as we supposed, but these spines, instead of being elon- 

 gate-triangular are sub-cylindrical or needle-shaped and projected 

 outwards at an angle of 45° or thereabouts, to the longitudinal 

 axis of the body. The cheek does not appear to be striated but 

 rather smooth. These two characters furnish additional grounds 

 for separating the species from C. antiquatus (Salter,) which has 

 the cheeks striated and the posterior angles of the head only 

 slightly produced into short broadly triangular terminations. 



2. The neck segment bears a short broad-based spine. The 

 first specimens collected do not exhibit this, but on reexamining 

 them I think I can see traces of it. Some of the specimens of C 

 coronatus (Barrande) lately collected in the Primordial Zone of 

 Spain have a spine on the neck segment of the same form as 

 that of C. minutus^ while others (according to the figures) have 

 not; and it may be that individuals of our species will yet be 

 discovered in which the absence of the spine can be clearly 

 established. This remark is made here because on comparing 

 the figures of the Bohemian and Spanish specimens of C. coro- 



