173 



the margin on one side, but elsewhere the shape is evenly conical. _The 

 inside of the shell is quite smooth, but the outside appears to be concen- 

 trically striated, at least it is so near the margin, where it is exposed for 

 about a line in height. The concentric striae are crossed by coarser striae, 

 radiating from the apex to the margin, two or three in one line. 



Diameter of the aperture 27 lines ; height of the shell 18 lines. 



Locality and Formation. Pauquette's Rapids, on the Ottawa River; 

 Black River limestone. 



Collector. E. Billings. 



ORTHOCERAS DRUMMONDI. (N. sp.) 



Fig. 156. 

 Fig. 156. Orthoceras Drummondi. 



Description. Shell small, apparently slightly curved ; section elliptical, 

 nearly circular, the lateral diameter being a little greater than the dorso- 

 ventral ; tapering at the rate of a little more than a line to the inch ; 

 from twenty to thirty septa in a length of one inch, those near the chamber 

 of habitation more closely crowded than those towards the apex ; siphuncle 

 small, slightly dilated between the septa, situated close to the margin, but 

 not in contact with the shell ; chamber of habitation proportionally deep, 

 with several obscure shallow undulations or constrictions of the shell. 

 Surface unknown. 



This species appears to be only two or three inches in length. Only 

 two specimens have been found however. The chamber of habitation is 

 10 lines in depth where the diameter of the- aperture is 5 lines. 



Locality and Formation. Near Kingston ; Black River limestone. 



Collector. A. T. Drummond, Esq., of Kingston, to whom the species 

 is dedicated. 



ORTHOCERAS VELOX. (N. sp.) 



Description. Shell rather large, slightly curved, tapering at the rate of 

 from twelve to fifteen lines in one foot of the length ; section circular ; 

 septa moderately concave, from six to nine in one inch ; siphuncle large, 

 cylindrical, marginal, in contact with the shell, its thickness about equal 

 to one-third the whole diameter of the shell. The surface of the shell is 

 marked with coarse, unequal, engirdling striae, distinctly impressed, from 



