48 



All of the specimens that have come under my observation are more or 

 less flattened by pressure, but the true form of the shell appears to be 

 gently and uniformly convex. 



Locality and Formation. — Montreal, in the Trenton limestone. Colling- 

 wood, in the Utica Slate. 



OoUectors. — Sir W. B. Logan, A. Murray, J. Eichardson. 



LiNGULA KiNGSTONENSIS. (N. Sp.) 

 Fig. 51. 



Description.— Ova,te or sub-pentagonal ; anterior angles rounded ; front 

 margin somewhat straight or gently convex ; sides nearly straight and par- 

 allel firom the anterior angles until -within one third the length from the 

 apex, then converging with a gently convex slope to the beaks ; apex 

 acutely rounded; apical angle about 90°. Surface with a smooth glisten- 

 ing aspect, and marked by minute concentric undulations of the shell. 

 Colour dark brownish-black. Length from 2J lines to 6 hues ; width 

 a little variable, from | to | the length, 



Somewhat resembles L. Huronensis but is smaller and more compressed 

 and does not exhibit the three flat planes of that species. It is more 

 closely allied to L. Progne from wliich it differs in being proportionally 

 shorter and broder. The specimens examined are nearly all flattened by 

 pressure but some of them which preserve the natural form very nearly 

 appear to be uniformly depressed convex. 



Locality and Formation. — Long Island near Kingston. Black River 

 limestone. 



Collectors. — J. Richardson and Mr. A. T. Drummond of Kingston. - 



LiNGDLA BrISEIS. (N. Sp.) 



Fig 52. 



Fig. 53. 



Fig. 54. 



Fig. 52. — Lingula Briseis. a and b, views of two specimens. 

 53. — L. Philomela. 

 54.— L. Cobourgensis. o, view of ventral valve. 6, longtiudinal section. 



