184 PA LJEONTOL OGYOFNEW YORK. 



COLEOrRION? tenuis, n. sp. 



PLATE XXXII, A, FIGS. 1, 2. 



Fossil a slender elongate, subcylindrical tube ; section apparently subelliptical. 



Length of specimen two centimetres, with a width, as presented in the 



stone, of scarcely one millimetre. 

 Surface marked by oblique, interrupted, undulating striae, which converge to 



a distinct longitudinal groove extending the entire length of the shell. 



The specimen is an extremely slender subcylindrical tube, which on one side 

 presents a distinct groove. The transverse striae, on approaching this groove, 

 are turned abruptly forward or apparently toward the larger extremity of the 

 shell. The characters presented are not precisely in accordance with the 

 generic description of Coleoprion, and I therefore refer the species with doubt 

 to that genus. 



Formation and locality. In shales of the Hamilton group, associated with 

 Tentaculites bellulus at Arkona, Ontario. C. W. 



COLEOLUS, n. gen. 



COLEOPRION, Hall (1S76). Not COLEOPRION, Sandberger (1847). 

 ORTHOCERAS, Yaxdkll and Shumabd. Geology of Kentucky, p. 15. 1847. 



Shell tubuliform, extremely elongate-conical, straight or -slightly curved, 



comparatively thick ; inner walls smooth. 

 Surface marked by annulating striae or rings which are more or less oblique, 



or sometimes rectangular to the axis : sometimes longitudinally striated. 



A critical study of other specimens of the species described by me as Coleo- 

 prion tenuicinctum has shown the impropriety of its reference to that genus. 

 The oblique elevated striae or annulations, characteristic of the genus, and 

 which were apparently interrupted by a longitudinal groove, are found to be 

 continuous, the apparent groove being due to fracture from compression of 

 the tube, as may be seen in figures 6-8, plate XXXII A, which present the 



