210 



Actinoceras Allumettense, Whiteaves 1891. Trans. Royal Soc. Canada, vol. IX. 



sect. 4, p. 85, pi. 10, figs. 3 and 3a. 



Lower Port Garry, Dr. R. Bell, 1880: a single specimen, a longitudinal 

 section of which is figured in the publication last cited. The specimen 

 is a little more than six inches in length, by nineteen millimetres in its 

 maximum diameter at the smaller end and thirty-six at the larger. It 

 was identified with the present species, with some confidence, after a 

 -careful comparison with four of Billings's types of 0. Allumettense, from 

 Paquette's Rapids, on the Ottawa River. A specimen collected by 

 Messrs. Dowling and Lambe at Black Bear Island, Lake Winnipeg, in 

 1890, which consists of a natural but much weathered longitudinal sec- 

 tion of the shell, about eight inches in length, in a piece of limestone, is 

 also probably referable to this species. 



A. Allumettense seems to be intermediate in its characters between 

 Actinoceras and Sactoceras, and should, perhaps, be referred to the latter 

 genus rather than to the former. Still, in the Orthoceras Richteri of 

 Barrande, which is stated by Professor Hyatt to be the type of his 

 genus Sactoceras, the height and breadth of the siphuncular segments, 

 which are moniliform rather than nummuloidal, are represented as nearly 

 equal, whereas in A. Allumettense these segments are nearly twice as 

 broad as high, and therefore more nearly nummuloidal. 



Actinoceras (Deirocehas) pyiHON, Billings. (Sp.) 



Orthoceras Python, Billings 18157. Geol. Surv. Canada, Rep. Progr. 



1853-f)C, p. 335. 

 Actinoceras [Deiroceras] python, S.js,tt 1883. Proo. Boston Soc. Nat. Hist., vol: 



XXir, p. 273. 



Clark's Point, on the west shore of Lake Winnipeg, about eleven miles 

 north of the mouth of the Little Saskatchewan, D. B. Dowliny, 1890 : a 

 natural mould of part of a siphuncle, shewing four of the "subglobular or 

 oval expansions " characteristic of this species. 



Actinoceras (Sactoceras 1) Canadbnse, Whiteaves. 



•Sactoceras Canadinse, Whiteaves 1891. Trans. Royal Soo. Canada, vol. IX., 



p. 85, pi. X., figs. 1, a-c. 



Orthoceras Canadense, S. A. Miller 1892. First Appendix to N. Am. Geol. and 



Palajont., p. B97. But not Orthoceras 

 Canadense, Billings, 1857, which, howevei, 

 is a synonym of Haroniii rertebralis, 

 Stokes. 



" Shell narrowly elongated, rather slender, somewhat fusiform, cylindro- 

 conical and increasing very slowly in thickness from the posterior end to 

 a .«hort distance beyond the midlength, thence narrowing slightly to the 

 aperture ; length about six times greater than the maximum thickness ; 



