126 The Ottawa Naturalist. [September 



eighty-four millimetres {2% inches) in length, by six mm. in 

 thickness at the smaller end and about fourteen at the larger- 

 Near the smaller end there are about ten annulations and near 

 the larger end about six, in a length of ten mm. The only other 

 specimen that the writer has seen, is a fragment about an inch 

 and a half in length, from the same formation and labelled Lot 

 42, Concession i, Cayuga, which is probably referable to this 

 species. It has about eight annulations in a length of ten mm., 

 at the larger end. 



O. Thestor, Hall,* is described as having proportionately 

 finer annulatio/is, and O. Idmoii, Hal],j- judging from the figure, 

 is almost cylindrical. 



Orthoceras Hagersvillense. (Sp. nov.) 



Shell of medium size, straight, longicone and increasing 

 slowly in thickness. Surface markings consisting of a fine rec- 

 tangular reticulation caused by the crossing of numerous equi- 

 distant and continuous, minute and close-set, longitudinal ridges, 

 by transverse but otherwise similar ridges. In the only speci- 

 men that the writer has seen, the longitudinal ridges are rather 

 less than a millimetre apart at the smaller end, and about a 

 millimetre apart at the larger ; while the transverse ridges are 

 slightly closer together, especially towards the larger end. Septa, 

 and shape and position of the siphuncle unknown. 



Corniferous limestone at Hagersville, collected by the writer 

 in 1890 ; a slightly distorted specimen, about three inches long 

 and an inch broad at the larger end, with a considerable portion 

 of its surface buried in the matrix. 



The species seems to be well characterized by the minute 

 reticulation of its surface, though its internal characters are 

 unknown. 



* Palaeontology of the Stale of New York, Vol. v, pt. 2, p. 302, pi. 82, fig. 18. 

 tlbid., p. 302, pi. 43, figs. II and 12. 



