20") 



and projecting belowthe hinge line, the shell extending about 

 one-third its length above the hinge line; surface marked by 

 fine spines above and coarse spine-bearing ridges below. 



Found in the Encrinal limestone, at Section 5. 



Productella spinulicosta. Hall. (Fig. 11 2.) (Pal. 

 N. Y., Vol. IV., p. 160, PL XXIII.) 





Fig. 112. Productella spinulicosta. Part of brachial valve enlarged, x 3, to show cardi- 

 nal process ; a small pedicle valve ; ventral, lateral, and cardinal views of a gibbous pedicle 

 valve, natural size (from Hall). 



Distinguishing Characters. — Broad, semi-elliptical, or some- 

 what orbicular, outline; strong- 

 ly incurved beak of pedicle valve, 

 which does not project belowthe 

 hinge line ; strongly - wrinkled 

 ears, bearing spines ; several rows 

 of interrupted spine bases, and 

 concentric striae or wrinkles. 



Found in the upper Moscow 

 shales, at Section 3 ; the Encrinal 

 limestone, Stictopora and De- 

 missa beds and shales below, to 

 the Strophalosia bed, at Sections 5, 6, 7, 8, in Eighteen Mile 

 Creek and Lake Shore Sections ; Transition and Marcellus 

 shales, on the Lake Shore. 



Note. — Productella shumardiana, Hall, described on p. 

 157, et seq., of Vol. IV., as occurring in the Marcellus and 

 Hamilton beds on the Lake Shore, is probably identical with 

 P. spinulicosta. 



Fig. 112A. A fragment of shale with 

 crushed specimens of Productella 

 spinulicosta, preserving the slender 

 spines (from Hall). (Specimens of 

 this character are found near the 

 anticline, at Section 3, upper Moscow 

 shale.) 



