432 UNrTED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 



with Morton's type, though attaining a very much larger size, and conse- 

 quently differing somewhat in the smaller details of the septa. In comparing 

 our figure of its septa with those of the smaller-sized individuals from 

 Alabama and New Jersey, it should be kept in mind that the details of the 

 septa of these shells vary according to the size of the specimen, and the 

 precise position of the subdivisions of the lobes and sinuses with relation to 

 the costse and nodes, which often, as it were, push aside and distort smaller 

 subdivisions. Indeed, I find, on comparison of different individuals, that no 

 two of them agree exactly in the minor details of the septa, those of gigantic 

 specimens like that represented by our figure 2, e, being much more complex 

 than in smaller individuals. 



The specimens of this species figured by Dr. Owen under the name 

 Ammonites Nebraseensis have the deflected part of the outer volution broken 

 away, in which condition they are, of course, undistinguishable from the 

 genus Ammonites, as formerly understood in its more comprehensive signifi- 

 cation. 



At least in external characters, S. pulcherrimus of Roemer, cited doubt- 

 fully in the foregoing synonymy, seems to be very closely allied to this spe- 

 cies, and I am much inclined to believe that a comparison of specimens may 

 show them to be identical. As Roemer does not figure the septa of his 

 shell, however, and only illustrates the exterior of an imperfect specimen, 

 this question can only be settled by a direct comparison of the shells them- 

 selves, or of good figures. 



Locality and position. — Dr. Morton's type-specimens of S. Conradi were 

 from the Upper Cretaceous beds of Alabama. It also occurs at the same 

 horizon in New Jersey. I have likewise seen specimens of it from the Sas- 

 katchewan, British America, in Professor Hind's collections. Our speci- 

 mens came from the same formation (Fox Hills group), at Fox Hills, Long 

 Lake, Moreau River, and near the eastern base of the Black Hills, Dakota. 



Scapliites Conradi, var. gtilosus, Morton. 

 Plate 36, fig. 1. 



Ammonites Conradi, var. gulosus, Morton (1834), Synop. Org. Rem. Cret. Group U. S., 39. pi. xvi, fig. 2. 

 Scapkites Conradi, var. gulosus, Gabb (1861), Synop. Moll. Cret. Form., 32. 



Compare Scapliites iris, Conrad (1856), Jour. Acad. Nat. Sci. Philad., Ill (n. s.), 335. 



Of this variety we have figured a perfect and well-marked specimen, 

 which agrees in almost every respect, excepting its larger size, with Dr. 



