New Genera and Species of Brachiopoda. 135 



Locality and formation. — L'anse a La Vielle. Gaspe Upper 

 Silurian. 



Stricklandia Canadensis, Billings. 



Description. — Shell very large, sub -circular, transversely broad, 

 sub-oval, often much expanded, compressed, surface covered with 

 rather obscure radiating ribs. The form is somewhat variable. 

 Usually the hinge line is straight and two thirds the greatest width 

 of the shell, the cardinal angles rounded, sides gently convex and 

 the front slightly pointed ; the ventral valve with a mesial sinus 

 commencing at the beak and gradually enlarging to the front; 

 the dorsal valve with a corresponding mesial fold ; both valves 

 about equally compressed convex; radiating ribs obscure one line 

 in width at the front. Average width of adult specimens five 

 inches, length the same or a little less, depth of both valves one 

 inch and a half. 



The proportioned length and width varies. In some specimens 

 the sides are so gently curved as to become sub-parallel and in 

 such instances the length is a little greater than the width, but in 

 general the latter dimension is the greatest. 



This species closely resembles S. liratus, and may perhaps be 

 considered a variety thereof, but at present on account of its great 

 size, I think it a distinct species. 



Locality and formation. — In great numbers at Mr. Goode- 

 now's Quarry, near Thorold, C.W., in the Clinton limestone. 



(Var.) Stricklandia brevis, Billings. 



Description. — Transversely oval, rather convex, hinge line a 

 little more than half the width of the shell cardinal angles, sides 

 and front rounded ; surface covered with obscure rounded radiat- 

 ing ribs from half a line to one line in width. Mesial fold and 

 sinus obscure width from two inches to two inches and a half; 

 length from one inch and three fourths to two inches. 



This form is closely allied to S. Canadensis but is proportionally 

 broader and more convex. The fossil figured in the Palaeonto- 

 logy of New York, vol. 2, p. 22, fig. 3, under the name of Spirifer 

 — appears to be the same. 



Locality and formation. — South West Point, Anticosti, Middle 

 Silurian. 



