39 



uncle " appears to be" " 6 lines from the dorsal and 3 lines from the 



ventral mai'gin." At any rate, in the writer's judgment, the eccentricity 

 of the siphuncle in this species, the only character by which it can be 

 distinguished from the Qyrtoceras Myrice of Hall and "Whitfield, is more 

 apparent than real and is probably due to distortion or to the accidental 

 and unequal erosion of the posterior end of the specimen. The shell of 

 0. Danoini is gently curved as is that of C. Myrice, and the exterior of 

 both is longitudinally grooved or fluted, the breadth of the grooves or 

 fuiTows in each case being about one line. 



Cyrtooeras Mtrioe, Hall and Whitfield. 

 Plate 6, flgs. 3 aud 3a. 



Cijrlowras Myrice. Hall and Whitf. 1875. Pal. Ohio, Vol. II., p. 149, pi. 8, fig. 9. 



Two specimens of this species, in excellent condition, have been col- 

 lected at Durham by Mr. Joseph Townsend, both of which are now in 

 the Survey Museum. One is a cast oi the interior of nearly the whole 

 of the septate portion of the shell, while the other, the one figured on 

 plate 6, shews the central and apparently moniliform siphuncle and 

 concave constriction of the body-chamber. The position of the siph- 

 part of the uncle was unknown in the typical Ohio examples of G. 

 Myrice, which, as stated in the remarks on the previous species, is 

 doubtfully distinct from Orthoceras Darwini. 



Ctrtoceras septoris, Hall. 



Gomphoceras septoris, Hall 1864, Eighteenth Keg. Kep., p. 350, flgs. 



9 and 10. 

 Cyrtoceras septoris, Hall and Whitfield. 1875, Pal. (_)liio, vol. 2, p. 151. 



Elora, R. Bell, 1861: A cast of the body chamber only, shewing the 

 very peculiui' aperture characteristic of this species. 



Phragmoceras Nestor, Hall, var Oanadense. 

 Plate 7, figs. 1, la, and lb. 



Phragmoceras Nestor, Hall 1867, Twentieth Reg. Eep. State of New York, 



p. 347, figs. 7 and 8. 

 Phragmoceras Nestor, Whitfield. Geology of Wisconsin, vol. 4, p. 301, pi. 19, fig. 3. 



Shell somewhat compressed, apparently very little cui-ved : septate 

 end expanding rapidly in the dorso ventral diameter, septa numerous, 

 the four- or five next to the body chamber averaging about five 



