114 



BRACHIOPODA. 



LiNGULA Canadensis. (N. sp.) 



Fig. 95. Fig. 96. 



Fig. 95. — Lingula Canadensis. — a, Dorsal (?) valve ; b, portion of surface enlarged 

 96.— i Forbesi. 



Description. — Shell large, oblong, sub-pentagonal ; front margin gently 

 convex or nearly straight ; anterior angles narrowly rounded ; sides 

 straight, and nearly parallel for about two-thirds the whole length, then 

 converging to the beaks ; apical angle about 130° ; cardmal edges on each 

 side of the beak nearly straight. The valves are moderately convex, 

 most tumid in the upper half, descending to the sides and front margin 

 with three flat slopes. Surface with fine, thread-like, elevated, longitudinal 

 ridges, five or six in the width of one line at the front margin ; these are 

 crossed by much finer concentric ridges, ten or twelve in one line, which 

 are continued over the longitudinal ridges, and give to the surface a 

 minutely nodulose appearance. 



Length about 1^ inches ; greatest width, at the anterior angles about 1 

 inch, and at the posterior angles about 1 line less. 



This species resembles in form, surface characters, and geological 

 position, the large L. tenuigranulata (McCoy). That species is, however, 

 proportionally a little longer, and is, besides, much more finely striated, 

 there being twenty-six longitudinal strige in the width of one line. 



Locality and Formation. — Anticosti, Black Pomt. Hudson River 

 group. 



Collector. — J. Richardson. 



