stanton.] LYTOCERATIDiE. 167 



of the western specimens is somewhat doubtful, though they agree 

 fairly well with the original description. Shumard states that the sep- 

 tum of his species has only four lobes, but it is evident from the de- 

 tailed description that he counted the lateral lobes on only one side, 

 so that there are really six. 



In form and surface ornamentation this species resembles Baculites 

 baculoides d'Orb.,butthe periodic constrictions on that species are nar- 

 rower and more distinct and the septa are much more complex. 



Baculites asper Morton? 

 PI. xxxvi, Figs. 4 and 5. 



Baculites asper Morton, 1834, Synopsis Org. Rem. Cret. Gr v p. 43, PI. 1, Figs. 12 and 

 13, PI. 13, Fig. 2. 



In the collection from Cinnabar mountain, Montana, there is a num- 

 ber of fragments of a small Baculites that are provisionally referred to 

 this species. They were first mentioned by Prof. F. B. Meek. 1 They 

 are associated with fossils of the Colorado formation. Becently Mr. 

 W. H. Weed has collected specimens of the same form on Mission 

 creek, northern Montana, associated with Pholadomya papyracea and 

 Inoceramus undabundus, both of which are Colorado fossils. 



The form is slender, very gradually tapering, rather narrow ovate in 

 cross section, and bearing on each side a row of distant more or less 

 prominent tubercles. The tubercles are usually rounded, but some- 

 times they are slightly elongated, taking a crescentic form. 



The diameters of the largest specimen are 14 mm and ll m,n . Nearly 

 all of the fragments are more compressed than this one. 



The septa are not deeply divided, and are characterized by the great 

 breadth of the saddles as compared with the lobes, but they are not 

 well enough preserved to show all the details. 



Mr. Gabb considered this species identical with B. anceps Lamarck, 2 

 but most other authors have regarded them as distinct. The type of B. 

 asper came from Cahawba, Alabama, but its exact strati graphic range 

 in that region is not yet known. A form that is certainly identical 

 with the one from Montana occurs in the Austin limestone of Texas 

 and was referred to Morton's species by Dr. Eoemer. 3 The material 

 now at my disposal does not permit me to determine whether the same 

 form occurs at a higher horizon or not. The one in the Montana and 

 Ripley formations that is usually referred to B. anceps seems to me cer- 

 tainly distinct from this one, and the fragments that Prof. Meek doubt- 

 fully referred to B. asper 4 are probably also different. 



i Ann. Kept, U. S. Geol. Sur. Terr, for 1872, p. 475. 

 2 Proc, Acad. Nat. Sci. Phila., 1861, p. 395. 

 3 Kreideb. v. Texas, p. 36. 

 «TJ. S. Geol, Sur. Terr., Vol. IX, p. 404, PI. 39, Fig. 10. 



