266 



Report of the State Geologist. 



83. Riiipidomella Leucosia. Hall. 

 1867, Hall, Pal. N. Y., vol. 4, p. 48, pi. 7. 



1892, J. Hall and J. M. Clarke, Pal. N. Y., vol. 8, pt. 1, p. 208, pi. 6a. 



This species occurs in the Encrinal limestone, where it is associated with 

 the preceding one. It also occurs in the shale below the Trilobite layers. 

 The specimens from the limestone are all very much exfoliated, and show the 

 surface features poorly ; the form and convexity being the only characters 

 indicating their identity. Those from the shales however are well preserved, 

 and show the characters of typical forms of this species. 



84. Riiipidomella Penelope, Hall. 

 1867, Hall, Pal. K Y., vol. 4, p, 50, pi. 6. 



1892, J. Hall and J. M. Clarke, Pal. N. Y., vol. 8, pt. 1, p. 208, pi. 6a. 



This species is common only in the Encrinal limestone, where the shells 

 attained their full size. The specimens obtained, though mostly exfoliated, 

 show the characteristic form, surface markings, and in some cases the muscular 

 impressions. It is, however, not so abundant as II. Varmxenvi. A number of 

 young individuals, apparently of this species, were obtained from the shale 

 beneath the limestone. A few large and well-developed specimens were found 

 in the two feet of shale below the Trilobite beds of Avery's creek. 



85. Riiipidomella idoneus, Hall. 

 1867, Hall, Pal. N. Y., vol. 4, p. 52, pi. 7. 



1892, J. Hall and J. M. Clarke, Pal. N. Y., vol. 8, p. 208. 



A few specimens of this species were found in the Encrinal limestone 

 and one in the lower Moscow shales three to five feet above the Encrinal 

 limestone. 



86. Riiipidomella cyclas, Hall. 

 1867, Hall, Pal. K Y., vol. 4, p. 52, pi. 7. 



1892, J. Hall and J. M. Clarke, Pal. K Y., vol. 8, pt. 1, p. 208. 



A single individual of this species was obtained from the two feet of 

 shales below the Trilobite beds of Avery's creek. 



