■WHITEAVE8.] LARAMIE AXD CRETACEOUS INVERTEBRATA. 41 



Protocardia subquadrata, Evans and Shumard. 



Plate 5, figs. 4, and 4 a. 



C'ardium mbrjvMfhatum, Evans and Shumard. 1857. Trans. Ac. Xat. Sc. St. 



Louis, vol. 1, p. 39. 

 Protocardia{Lq)tocardia)mhrjv.adrata,'Meek {as ofE. and S.). 1876. Eep. U.S. 



Geol. Surs'. Terr., vol. IX., p. 175, pi. 29, 



figs. 8a, b, c, d, e. 



South Saskatchewan, opposite Swift Current Creek, E. G. McConnell, 

 1882 : very abundant. Bull's Head, about twenty-two miles west of 

 the west end of the Cypress Hills, E. G. ilcConnell, 1883 : not uncom- 

 mon. Three miles north of Eoss Coulee, near Irvine Station, on the 

 Canadian Pacii:c Eailway., T. C. Weston, 1884 : a number of casts of 

 the interior of the closed valves. Fcjur miles south of Battle Eiver, 

 Township 38, between Eanges 12 and 13, west of 4th Meridian, J.B. 

 Tyrrell, 1884. 



Some badly preserved, imperfect and immature specimens of a 

 small Protocardia collected by G. M. Dawson on the Smoky Eiver, in 

 18*79, which were referred by the writer to the P. rara of Evans and 

 Shumard in a provisional list of the fossils of that locality on page 124 

 B. of the " Eeport of Progress" of the Canadian Survey for 1879-80, 

 most probably also belong to the present species. 



Protocardia borealis. (X. Sp.) 

 Plate 6, figs. 1, 1 a, 2, 2 a, and 3. 



Shell of medium size for the genus, specimens varying ft-om a little 

 less than an inch to an inch and five-eighths in length ; valves rather 

 strongly convex, thickest just above the mid-height; lateral out- 

 line varying in different specimens from rounded subquaiirangular to 

 •obliquely and broadly subovate ; length slightly exceeding the maxi- 

 mum height. Anterior side very short, its extremity regularly 

 rounded; posterior side rather longer than the anterior, its extremity 

 somewhat obliquely sub-truncated above, and rather narrowly rounded 

 at the base below. Superior border descending very abruptly in front 

 of the beaks, nearly straight and parallel to the ventral margin behind, 

 cardinal margin short, ventral margin nearly straight in the middle 

 and for the greater part of its length ; umbones broad, oblique, and 

 obtusely angular behind ; beaks placed in advance of the middle (in 

 some specimens very near to the anterior margin) curved inwards and 

 downwards with a slightly forward inclination. 



