274 



Report of the State Geologist. 



107. Spirifer sculptilis, Hall. 



1867, Hall, Pal. N. Y., vol. 4, p. 221, pi. 35. 



This species was obtained only from the Encrinal limestone, and only a 

 few specimens were found. The specimens are usually exfoliated but the 

 characteristic lamellae are well shown. 



108. Spirifer consobrinus, D'Orbigny. 



1850, d'Orbigny, Prodr. d. Paleont. t. 1, p. 98. 



1867, Hall, (S. zigzag) Pal. N. Y., vol. 4, p. 222, pi. 35. 



This species has been found only in the Moscow shales at Eighteen-mile 

 creek, where it occurs quite abundantly in the beds from two to five feet 

 above the Encrinal limestone. The typical forms are the most abundant, but 

 some specimens occur which might at first glance be mistaken for robust 

 specimens of S. mucronatus. The small number of plications, the even zigzag 

 concentric lines, and the relatively high and curving area of the pedicle-valve, 

 however, distinguish this species: The variety designated as 8. Clio by 

 Hall occurs occasionally. A comparison with S. mucronatus, from Thedford 

 Ontario, is made above. 



109. Spirifer granulosus, Conrad. 



1867, Hall, Pal. N. Y., vol. 4, p. 223, pi. 36, 37. 



1893, J. Hall and J. M. Clarke, Pal. N. Y., vol. 8, pt. ii, p. 39. 



This species is eminently characteristic of the Demissa and Pleurodictyum 

 beds, in both of which it occurs in great abundance. Two specimens were 

 obtained at Section C, about a foot below the S. demissa bed. The specimens 

 from the latter are robust, and usually in a fairly perfect condition, with both 

 valves intact. Those from the Pleurodictyum beds are likewise robust, and 

 usually overgrown by bryozoa. The species occurs sparingly in the shales 

 below the Trilobite layers. It is rare in the Nautilus bed, and extremely so in 

 the Strophalosia bed. It has not been observed below this level. The species 

 is common in the upper part of the Encrinal limestone, where the variety 

 with the angular sinus (S. Clintoni, Hall) is likewise abundantly repre- 

 sented. The species does not usually occur above the Encrinal limestone, 

 though a much worn fragment was found in the lower Mosco^v' beds as 

 before noticed. 



