BRACHIOPODA — TELOTREMATA. 



325 



nent and much elevated beak, incurved over the high arcuate area. 

 Sinus wide and deep. Brachial valve with small beak, slightly in- 

 curved over a nearly vertical, narrow cardinal area. Fold promi- 

 nent and angular. Surface marked by 6 to 10 plications on each 

 side of the fold and sinus, while 3 or 4 smaller bifurcating plications 

 are usually present on fold and sinus. Concentric lines present on 

 well preserved specimens. 



Onondaga of New York, Ohio and Kentucky. 



343. S. (Delthyris) raricosta Conrad. (Fig. 412,/-//.) Devonic. 

 Gibbous, with rounded cardinal extremities. Pedicle valve with 



greatly elevated beak incurving over the high cardinal area. 

 Brachial valve with small arching beak. Surface marked by 2 to 

 4 strong rounded ribs on each side the median line, crossed by 

 concentric lamellose strise and marked by fine and close radiating 

 striae. 



Onondaga of Maine, New York, Ohio, Kentucky, Indiana, Ne- 

 vada, Ontario, Quebec. 



344. S. varicosus Hall. (Fig. 413, a-c.) Devonic. 

 Small, with length not exceeding half the width. Hinge ex- 

 tremities angular or mucronate. Pedicle valve much the more 



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Ml W 



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Fig. 413. a-c, Spirifer varicosus ; d-e, Spirifer enryteines. (After Nettleroth. ) 



convex with high cardinal area. Surface distinguished by the 

 strong lamellose lines of growth which give it a varicose ap- 

 pearance. 



Onondaga of New York, Ohio, Kentucky, Nevada, New Bruns- 

 wick. 



