No. 109.] 59 



eating lamellose strise, which are more or less prominent, de- 

 pending on the condition of preservation in the shell : surface 

 of lamellse ornamented by short fine vertical strise or crenula- 

 tions, which project in fimbrise on the edge of the lamellse. 

 This species resembles in its surface characters the Spirifer crispus of 



the Niagara group, but is much larger, has a greater number of plications 



and a narrower and longer area, while the valves are more nearly equal in 



size. 



Geological position and locality. Lower Helderberg limestones, Albany 



county. 



SpIEIFER MULTISTRIATUS ( n. S.). 



Pal. N.Y. Vol. iii, pi. 24, f. 3. 



Shell transversely oval, or pentagonal with the angles rounded : 

 ventral valve moderately convex towards the beak, with a broad 

 ( not sharply defined ) sinus below, which often becomes obsolete 

 before reaching the beak ; beak abruptly incurved over the beak 

 of the opposite valve : dorsal valve more convex than the op- 

 posite, the middle elevated in a broad scarcely defined lobe • 



Spirifer muitistkutus. 



