SILURIAN FOSSILS. 



287 



which hold fossils of the Chazy, Black 

 River and Trenton limestones, and 

 from near Cornwall and the Island 

 of Montreal in the Chazy. 



Besides the above there are several 

 small nearly circular fossils from Punk 

 Island, which appear to be casts of 

 some lamellibranchiate shell. 



Gasteropoda. 



Trochonema umbilicata (Hall, Sp.) 

 This species occurs at Lake Winnipeg 

 and at the Little Saskatchewan in 

 considerable numbers. A species 

 allied to Pleurotomaria rotuloides 

 (Hall) is common at Punk Island, 

 and a Maclurea allied to M. Logani 

 (Salter), but with more slender whorls 

 was found at Punk Island and the 

 Little Saskatchewan. One of the 

 specimens has the operculum in place, 

 but is destitute of the shell and some- 

 what distorted. None of the Gaster- 

 opoda have the shell preserved. . 



Cephalopoda. 



ORTHOCEEAS SIMTSONI. (N. S.) 



The specimen is a portion of the 



siphuncle, nine inches and one-fourth 

 in length, eleven lines in diameter 

 at the larger extremity, and ten at Orthocekas Simpsoni 

 the smaller. It is nearly cylin- 



A fragment of the siphuncle of 

 this species. 



