78 WIILTEAVES ON THE 0ET*H0CEEATID.E OF 



of the Nclsou River specimens are broadly elliptical, but this appearance is probably due 

 to the abnormal compression to which they have been subjected. 



Endoceras subannulatum, Whitfield. 

 Plate V, tigs. 2 and 2a. 



Endoceras (Camcroceras) suhamndatum, Wliitfiel't. 1882. Geol. Wiscoiis., vol. iv, p. 230, pi. vii, figs. 15 and 16. 



Numerous examples of a large annulated Endoceras, which in many respects agree 

 fairly well with Professor Whitfield's description of this species, have been collected in 

 the valley of the Red River, on the western shore of Lake Winnipeg and on many 

 small islands in that lake. Specimens in which the annulations of the exterior are 

 preserved were obtained at East Selkirk by Dr Bell in 1880, by Messrs. T. C. Weston 

 and A. McCharles in 1884 and by Mr. L. M. Lamlm in 1890 ; at Grindstone Point, Lake 

 Winnipeg, by Mr. Weston in 18S4, and by Mr. J. B. Tyrrell in 1889 ; near Cat Head, by 

 Mr. Donald Gunu in IS-IS ; at Swampy or Beren's Island, by Mr. Tyrrell in 1889, and by 

 Messrs. Dowliug and Lambe in 1890; at Suake Island, Jack Head Island (near Pike 

 Head), Black Island (near Beren's Island), and at Big Sturgeon Island, by Messrs. Dowling 

 and Lambe in 1890. Very large but badly preserved specimens, which probably belong 

 to the same species but which do not shew the characteristic surface ornamentation, 

 were collected at Lower Fort Garry and at Dog's Head, Lake Winnipeg, by Mr. Weston 

 in 1884 ; at Big Island, by Mr. Tyrrell in 1889 ; at Black Bear Island (near Snake Island), by 

 Messrs. Dowling and Lambe in 1890 ; and at Commissioners' (or Cranberry) Island by Mr. 

 Dowling in 1890. 



The largest specimen in which any considerable portion of the test is preserved is 

 the one from East Selkirk collected by Mr. McCharles, the posterior moiety of which is 

 represented by figure 2, on Plate V. It is upwards of seventeen inches and a half in 

 length, three inches and a half in thickness at the smaller end and about four and a 

 quarter at the larger. It is septate throughout and its transverse annulations are com- 

 paratively narrow, there being five to an inch. The largest specimens without the test 

 are upwards of two feet in length, and imperfect at both ends, while a large fragment, 

 which, however, has been abnormally compressed, is eight inches in breadth by about 

 fifteen in length. All of these also are septate throughout, and, so far, not a trace of the 

 chamber of habitation can be found in any of the specimens from Manitoba. This is the 

 more remarkable when it is borne in mind that the Wisconsin specimen of E. subannulatum 

 figured by Professor Whitfield, which is represented as only two inches in breadth at 

 the larger end, has no less than three inches and three quarters of the body chamber 

 preserved and only about an inch and three quarters of the septate portion of the 

 shell. 



In Endoceras annulatum the septa are stated to be " more approximated than the annu- 

 lations," but in the present species the opposite is the case, the sutures of the septa being 

 usually about twice as far apart as the breadth of the annulations. In the Manitoba 

 specimens, which may possibly prove to be distinct from the typical E. subannulatum, 

 there is a considerable amount of variation in the proportionate thickness of the annula- 



