[MATTHEwJ STUDIES ON CAMBRIAN FAUNAS 181 



Among the fossils from Hastings Cove are a number of examples 

 which agree fairly well with Billings's description of this species, which is 

 ^8 follows : 



'•Head, broad, semi-circular, moderately convex ; glabella, oblong- 

 conical, nearly two-thirds of the whole length of the head ; the front, 

 obtusely rounded or somewhat straight ; the anterior angles, nari'owly 

 rounded ; the sides, nearly straight from the anterior angle to the neck 

 furrow, just in advance of which is the widest part. The neck furrow, 

 well defined all across ; the glabellar furrows, indistinct ; the dorsal 

 furrow, well defined all around the glabella. The cheeks are moderately 

 tumid ; a line drawn across the glabella, about the mid-length, would 

 pass through the eyes. The distance of the eyes from the dorsal furrow 

 is equal to the greatest width of the glabella ; the eye appears to be very 

 small. The margin in front of the glabella is equal in width to about 

 one-third of the whole length of the head ; it is bordered by an obtuse, 

 narrow, elevated rim, just within which is a groove which is more deeply 

 impressed on each side than directly in front of the glabella, there being 

 at this place a gently convex elevation resembling that which occurs in 

 Barrande's species, C. Sulzeri and C. coronatus. The ocular ridge is well 

 defined where the surface is preserved, but is rarely visible in the sand- 

 stone casts. Most of the specimens are distinctly carinate along the 

 median line of the glabella. It is possible that there may be a tubercle 

 on the neck segment, but none of our specimens have this part suflftciently 

 well preserved to show it. The following are the dimensions of a speci- 

 men of the average size : Length of head, 5 [3^]^ lines ; length of glabella 

 (and occipital ring), 3|^ [2^] lines ; greatest width of glabella, 2 lines ; 

 width of glabella in front, \\ lines ; distance of eye from the side of the 

 glabelhi [near]}-], 2 lines. Dedicated to Prof. C. B. Adams, late State 

 Geologist of Vermont. Locality and Formation — Highgate, Vermont, in 

 the Potsdam Group, about a mile east of the Highgate Spring. Collectors 

 — Eev. J. B. Perry. Dr. G. M. Hall and E. Billings." 



Among the fossils from Hastings Cove there are a number of heads 

 which agree fairly well with this species. Ail are somewhat narrower, 

 and they are devoid of the swelling of the area in front of the glabella, 

 which is mentioned by Billings as a character of C. Adamsi ; he does not, 

 however, show any such swelling in his figure of the species. The form 

 from Hastings Cove, however, shows on some examples a character 

 common in the Conocorj'phea, viz., an enlargement or boss on the ocular 

 fillet close to the glabella. 



The proportion of the parts of the head in the Hastings Cove form 

 are closely those given above by Billings for the type, exccjit that the 



iThe corrected dimensions are in accord with Billings'.s description, figure, and 

 the supposed type in the Museum at Ottawa. 



