70 BULLETIN OF THE 



Camerella. 

 Camerella ops Billings. New Species of Low. Sil. Fossils ; Can. Geol. Sur- 

 vey, 18C2, p. 148. 



Spirifer Sowerby. 



Spirifer tenuistriatus Shaler. 



Form about the same as Spirifer radiatus Sow.; hinge-line straight for four 

 fifths of the diameter of shell, then gently rounding; transverse diameter a 

 little greater than from umbo to border ; soeketxvalve very convex, most 

 prominent point about middle of valve ; umbo rising above the hinge-line 

 for a distance equal to one fifth the transverse diajneter ; strongly recurved ; 

 area indistinctly bounded. Socket-valve about two fifths as projecting as 

 toothed valve ; umbo rising a little above the hinge-line; evenly rounded; 

 mesial sinus rather shallow; somewhat angular. Surface covered with very 

 fine, almost microscopic radii ; eight or nine in the space of one line on the 

 border. 



This species differs from S. radiatus in the minuteness of the radial striee. 

 It is possible that this form is identical with the S. radiatus of Hall, from 

 the Niagara and Clinton of New York. No comparison of specimens has 

 been made. — Near Southwest Point, upper part of Division F, Canada 

 Geological Survey. 



Fublished June, 1865. 



