282 



Report of the State Geologist. 



Genus Camarotcechia, Hall. 



127. Camarotcechia Horsfordi, Hall. 



1867, Hall, Pal. N. Y., vol. 4, p. 339, pi. 54 (Rhynchonella). 



1893, J. Hall and J. M. Clarke, Pal. N, Y., vol. 8, pt. ii, p. 189, pi. 57. 



This species is rare at Eighteen-mile creek. I have found it in the 

 Encrinal limestone, and in the shale immediately below. A doubtful specimen 

 from the Nautilus bed may belong here. A specimen from the lower Moscow 

 shales three feet above the bottom also belongs to this species. 



128. Camarotcechia Sappho, Hall. 

 1867, Hall, Pal. N. Y. vol. 4, p. 340, pi. 54. 



1893, J. Hall and J. M. Clarke, Pal. N. Y., vol. 8, pt. ii, p. 189, pi. 57. 



This is the most common species of the genus in these shales. It is 

 sparingly represented in the Pleurodictyum beds, but has not been noticed 

 below them. The species occurs quite abundantly from seventeen to twenty- 

 one feet below the Encrinal limestone. Above this it does not occur again 

 until within three feet of the Encrinal limestone, between which and the lime- 

 stone, as well as in the latter rock, a number of specimens were found. On 

 one of these the plications are too few in number to agree with the typical 

 forms with which it otherwise corresponds. 



129. Camarotcechia dotis, Hall. 

 1867, Hall, Pal. N. Y., vol. 4, p. 344, pi. 54. 



1892, Hall and Clarke, Pal. X. Y., vol. 8, pt. ii, p. 189, pi. 57. 



This species, originally described from a calcareous layer in the Hamilton 

 of Eighteen-mile creek, occurs, so far as I am aware, at that place only in the 

 Encrinal limestone, where it is rare. In the Nautilus bed of Avery's creek 

 and the lake shore, however, it is very common, the specimens being of aver- 

 age size. The number of plications on the fold varies from four to five, and 

 m the sinus from three to four. Occasionally additional plications appear 

 on the sides of the fold. The plications are usually rounded, sometimes 

 strongly so. Four measurements gave dimensions as follows: Length 10, 

 9.5, 10, 9, mm and width 12, 12, 12, 10, mm respectively. A doubtful speci« 

 men was obtained from the Strophalosia bed. 



