286 ASSINNIBOINE AND SASKATCHEWAN EXPEDITION. 



Echinodermata. 



Columns of a large Glyptocrinus allied to G. ramulosus 

 occur at Punk Island and Grindstone Point ; and besides 

 these, at the latter locality were found several plates of a 

 Glyptocystites closely allied to G. multiporus. 



Brachiopoda. . 



Two specimens of a plaited Rhynconella a little smaller 

 than E. plena were found at Punk Island. 



Lamellibranchiata. 



MODIOLOPSIS PARTIUSCTJLA. (N. S.) 



This species closely resembles M. modiolaris (Conrad) 

 but is always much smaller. It is transversely elongate, 

 anterior extremity small, rounded half the width of the 

 posterior ; the latter obliquely truncated and somewhat 

 straight from the end of the hinge line for rather more 

 than half the width, then rounded at the lower posterior 

 angle. Hinge line straight or a little arched, full three- 

 fourths the whole length of the shell. The umbones are 

 less than one-fifth the length from the anterior extremity. 

 The valves are moderately convex, obscurely and obliquely 

 carinate from the umbones towards the lower posterior 

 angle. In many specimens the ventral margin is concave 

 near the anterior extremity, as if for the purpose of a 

 byssus. Surface with obscure concentric undulations of 

 growth. Length of large specimen, one and a half inch. 

 In general they are a good deal smaller. 



This shell so much resembles M. modiolaris that I have 

 long hesitated as to the propriety of giving it a separate 

 name. It is very widely distributed, since we have speci- 

 mens from Lake Winnipeg at Punk Island, from the 

 Pallideau Islands in Lake Huron, where it occurs in strata 



