205 / 



other. Judging by its thickness, No. 2 could very well have formed' 

 part of the anterior end of No. 1, and both are from the same locality. 

 At the rate of taper of three-tenths of an inch per foot, it is estimated 

 that specimen No. 1 would have to be eight inches longer anteriorly 

 than it now is before it could be as thick as No. 2. This would give 

 thirty -five inches for No. 1, eight for No. 2 and eight for the interval 

 between them, or a total of four feet and a quarter for the siphuncle 

 only, which, even then, would be imperfect at both ends. 



" In their proportionate thickness and probably submarginal position, 

 as well as in the irregularity and gradual expansion of their endosiphons, 

 these siphuncles seem to agree better with those of Endoceras than 

 with those of Orthoceras proper. Although no clearly defined sheath or 

 sheaths have yet been detected in them, they appear to be most nearly 

 related to that section of the genus Endoceras which Professor Hyatt 

 has differentiated under the name Sannionites, Waldheim, and in this 

 view of their affinities the writer's opinion was endorsed by Professor 

 Hyatt,'' who, however, has since indicated a new genus of Endoceratidse, 

 which he proposes to call Narthecoceras, and based upon these siphuncles 

 and those of Orthoceras Simpsoni, Billings. Specifically, these siphuncles 

 also seem to difier from those of 0. Simpsoni in their huge size and 

 proportionate thickness, but more especially in their more rapid increase 

 in thickness, though this increase is still so very gradual as to be not 

 readily appreciable in the comparatively short fragments that are usually 

 obtained." 



Endoceeas (Naethecoceras) Simpsoni, Billings. (Sp.) 



Orthoceras Simpsoni, Billings 1859. In Hind's Rep. Assinib. andSaskatch. 



Bxpl. Exped., p. 186, pi. 1, fig. 1. 

 M M Whiteaves 1891. Trans. Royal Soe. Canada, vol. IX., 



sect. 4, p. 80, pi. 7, figs. 2 and 2a, and pi. 



8, fig. 1. 

 Narthecoceras (Endoceras) Simpsoni, Hyati. .1895. Amer. Geol., vol. XVI., p. 3. 



"The type of this species, which is still preserved in the Museum of the 

 Geological Survey, was collected by Professor H. Youle Hind in 1858 at 

 Cat Head, on the western shore of Lake Winnipeg, and is thus described 

 by the late E. Billings. The specimen is a portion of the siphuncle, nine 

 inches and one-fourth in length, eleven lines at the larger extremity,, 

 and ten at the smaller. It is nearly cylindrical, with a broad, shallow 

 constriction above and below each of the narrow annulations which mark 

 the attachment of the septa. There are eight of these septal rings at 

 the following distances from each other, commencing at the smaller 

 extremity : Between the 1st and 2nd, fourteen lines ; 2nd and 3rd, twelve 

 lines ; 3rd and 4th, ten and a half lines ; 4th and 5th, thirteen and a. 



