191) 



Stropheodonta (Pholidostrophia) xacrka. (Hal 

 (Pig. 102.) (Pal. N. Y., Vol. IV., p. 104, PI. XVIII.) 



Dis tinguishing Charac- 

 ters.— Small size; convex 

 character; smooth and na- 

 creous surface; interior of 

 the brachial valve with three 

 diverging ridges in front of 

 the muscular area. 



Found in the Encrinal 

 limestone, at Section 5 



(common); in the ModlO- Fig. 102. Stropheodonta nacrea. Dorsal, 



, , 7 . , , profile and ventral views of a specimen; in- 



niOrj)hnSUbahltclOea[Vi\W); teriors of pedicle and brachial valves (from 



m . ' . , n • ,1 Hall). 



I rilobite beds (especially 



the lower), at Section 8, on the Lake Shore and in Avery's 

 Creek (frequent); shale below the Trilobite beds, in Avery "s 

 Creek (rare). Schuchert refers this species to S. (P.) 

 iowamsis. (Owen.) (Bull. 87, U. S. G. S.) 



Stropheodonta (Leptostrophia) junia. Hall. (Fig. 

 103.) (Pal. N. Y., Vol. IV., p. 108, PI. XVIII., S. textilis.) 



Fig. 10.3. Stropheodonta junia. Dorsal view of a large individual, showing the cardinal 

 area of the ventral (pedicle) valve; enlargement of the surface striae (from Hall). 



