New Fossils from the Winnipeg Limestones. 391 



Longitudinal sections through the centre of large speci- 

 mens shew that the calyx is not very deep, and that its 

 cavity occupies but a small proportion of the entire 

 length. Below the calyx the corallum is filled with 

 strongly developed and apparently thickened septa, with 

 well-marked dissepiments between them, and these septa, 

 with their dissepiments, unite in the centre in such a way 

 as to form a large irregularly reticulated pseudo-columella, 

 which projects slightly above the centre of the base of 

 the calyx, as a boss of irregular shape, but with a narrowly 

 rounded summit. 



This fine coral is especially abundant, and attains to a 

 large size in the Ked River valley, at St. Andrews, Lower 

 Fort Garry and East Selkirk, Manitoba, where it was 

 collected by Dr. R Bell in 1880, by T. C. Weston and 

 A. McCharles in 1884, by L. M. Lambe in 1890, and by 

 I). B. Dowling in 1891. On the western side of Lake 

 Winnipeg a few rather smaller and much less perfect 

 specimens of this coral were collected at Jack Head 

 Island, Manitoba, by I). B. Dowling and L. M. Lambe in 

 1890, at Dog Head, Manitoba, Selkirk Island, Keewatin, 

 and on the main shore off the north end of Selkirk 

 Island, Saskatchewan, by D. B. Dowling in 1891. A 

 small specimen, which is apparently referable to this 

 species, was collected at the junction of the Little and 

 Great Churchill rivers by Dr. R. Ball in 1879. 



Streptelasma robustum appears to be readily distinguish- 

 able, by its very much larger size and much more robust 

 habit of growth, from the well-known S. corniculum of 

 Hall. It seems to bear somewhat the same kind of 

 relationship to S. corniculum that the Beceptaculites Oweni 

 of the Cambro- Silurian rocks of the west does to the 

 eastern fossil known by the rather inappropriate name of 

 R. occidentalis, and that Murcliisonia teretiformis (or M. 

 major) of the same rocks does to the eastern M. bellicincta. 



