212 



linear area of brachial valve ; slightly incurved beak ; 

 well-raai'ked mesial fold and sinus; simple surface plications; 



Fig. 119. ispirijer aiidactdus. Dorsal and front view of a specimen; dorsal and ven- 

 tral views of another specimen, with a higher area and more projecting ventral beak (from 

 Hall;. 



numerous, often imbricating', concentric lines, and fine 

 radiating stria*. 



Found in the lower Moscow shale, at Sections 4 ;uid 5 

 (rare); also var. eatoni ; Encrinal limestone, at Section 5 

 (common); Stictopora and Deniissa beds, at Section 5 

 (abundant) ; four feet below the Encrinal limestone, at Sec- 

 tion 6, etc. (rare) ; shales between the Trilobite beds, at 

 Section 8, and on the Lake Shore; Pleurodictyum beds, in 

 Avery's Creek, and on the Lake Shore. 



Spirifer AUDAcuLrs, var. j:atom. Hall. (Fig. 119A.) 

 (Pal. X. Y.. Vol. IV., p. 229, PL XXXVIIL ) 



Distinguishing- Cii^iracters. — Eobust, extremely convex 

 and resembling a small S. granulosus, but without the 

 granules. 



Found in the lower Moscow shale, at Section o, coral 

 laver. 



