50 



LiNGULA COBOURGENSIS. (N. Sp.) 



Fig. 54. 



Description. — Almost regularly oval ; greatest width about the middle ; 

 length one-fourth gi'eater than the width ; anterior extremity uniformly 

 rounded ; apex obtusely angular ; both extremities sub-equal ; sides gently 

 convex. Both valves are moderately convex, and one of them has some- 

 times an irregular furrow extending from near the beak along the median 

 line for one-half or three-fourths the length. Colour, dark brown, with 

 some shades of light brown or yellow ; general aspect smooth and shining, 

 with fine concentric undulations of growth, which become fine, elevated, 

 sharp, closely crowded stride, on each side of the beak ; longitudinal striae 

 are visible on some specimens. 



Length, about 1 inch ; width, about f of an inch ; depth of both valves, 

 3 or 4 hues. Smaller specimens occur associated with the larger. 



Although the specimens appear to be abundant, I have never seen one 

 with the beaks entire. L. obtusa (Hall)is a smaller shell, wider in front 

 and of a black colour. 



Locality smd For7natio7i. — Cobourg, Trenton limestone. Also at Col- 

 lingwood, in the same formation. 



Collectors. — T. Devine, Esq., Crown Lands Dept., Mr. J. F. Smith, 

 Toronto, R. Bell. 



LiNGULA Daphne. (N. sp.) 



LiNGULA ATTENUATA, (Hall,) Pal. N. F., Vol. 1, p. 94, PI. 30, figs la 16, Not L. atteii' 

 uata, (Sowerby.) 



Description. — Shell ovate, broadest in the anterior half, moderately 

 pointea in the rostral half; front margin uniformly rounded ; sides in the 

 lower half gently convex, and in the upper somewhat straight or slightly 

 curved and converging to an angle of between 60° and 70° at the apex. 

 The valves are uniformly convex, the greatest tumidity being in the upper 

 half. Surface with fine concentric striae and occasionally minute vmdula- 

 tions of the shell resembling striae to the naked eye. 



Length, from 4 to 8 lines ; width varying from | to f the length. 



This species has been referred to L. attenuata, Sowerby, but it diffei'S 

 therefrom in having the front uniformly rounded. In the English species 

 the front margin is nearly straight in the middle, and the sides in the lower 

 half also nearly straight and parallel. 



Locality and Formation. — Montreal. Trenton limestone. 



Collectors. — Sir W. E. Logan, J. Richardson. 



