MOLLUSCA OF LOWER CANADA. 107 



Vertigo simplex, Goulcl. Riviere du Loup : J. F. TV. Valley 

 of the Marsouin: along the'Restigouche and at Metis : R. B. 



Vertigo Gouldii, Binney. Island of Orleans, and Riviere du 

 Loup : J. F. TV. Sixteen-Lland lake. TV. D. Montreal Moun- 

 tain : R. J. F. 



Vertigo ovata? Say. Montreal mountain : R. J. F., and J. F. TV. 

 The only specimen taken was not quite adult, but appeared to 

 belong to this species. 



Carychium exiguum, Say. Sixteen-Island lake, one specimen : 

 W.D. 



DESCRIPTIONS OF NEW, OR IMPERFECTLY KNOWN SPECIES. 



SPHCERTUM. 



(Section A. Species with Rounded but not Protuberant Beaks.) 



Figure 1. 

 Sphcerium sulcatum, Lamarck. 



Animal white ; tubes, a light orange color. 



Shell transversally oval, nearly equilateral, light in texture for 

 its size ; posterior margin somewhat more pointed : anterior 

 rounded ; base slightly curved ; valves convex ; beaks full raised 

 above the outline of the shell; posterior portion a little longer; 

 sulcations coarse, regular ; epidermis dark chestnut brown ; interior 

 light blue ; hinge margin narrow, nearly a straight line ; cardinal 

 teeth small, indistinct, situated somewhat towards the anterior 

 side, double in both valves, and so placed as to assume the shape of 

 the letter V reversed; lateral teeth on a line with the primary 

 teeth, large, strong and prominent. 



Long. 11-16; lat. 71—61 ; diara. 5-16 inches. 



The young is more equilateral than the adult, and more com- 

 pressed; it presents the shape of a quadrilateral, and is of a light 

 iemon colour: the striations areas heavy as those of the mature 

 shell. The hinge-margin is generally straight, but,in specimens from 

 Alabama, Pennsylvania, and Rhode Island it is slightly curved. 



