224 



\ 



shape and position of its siphuncle. As seen in a longitudinal section, 



the siphuncle of the Nelson River specimen is nummuloidal, expanded, 



about twice as broad as high between the septa, and plaiced at a distance 



not much less than its maximum breadth from the margin of the side of 



the convex curve. 



Cybtoceras laticuevatum, Whiteaves. 

 Cyrtoceras laticurvatum, Whiteaves 1896. Canad. Rec. (^c, vol. VI., p. 365. 



Fig. 14. Cyrtoceras laticurvatum. Outline of a longitudinal section of a 

 specimen from Little Black Island, one-half the natural size. 



" Shell large (attaining to a length of about twelve inches, as measured 

 along the convex and presumably ventral curve), narrowly fusiform and 

 broadest at a short distance from the body chamber, elongated, slender 

 and so much curved as to form a broad semicircular arch, which is 

 straighter anteriorly than posteriorly : sides compressed, the outline of a 

 transverse section of the broadest part being elliptical : body chamber 

 compressed cylindrical, more than twice as long as broad, and occupying 

 about one-third of the entire length. 



" Surface markings unknown, though there are indications of faint 

 longitudinal ribs on one of the casts. 



