TABLE VIII. 



AMJIONITES AND SCAPHITES, FROM THE CKETACEOUS FOKMATION OF NEBRASKA. 



All, except Figures 6 anrl 3 a, medal-ruled on Steel from the Original Specimens. 



Tab, VTII., Fig, 1, Ammonites Nicolhtii, Morton. Fox Hills, between the Cheyenne and Moreau Rivers, 



This Ammonite agrees v/ith Morton'.s description of tlie above species, published in the Journal of the 

 Academy of Natural Sciences, vol. viii., p. 209, except that the costas are closer together, are more 

 numerous, and their bifurcations repeated sometimes tvi^ice before reaching the periphery; distinctions 

 which are, however, not considered sufficient for the establishrnent of a new species. 

 There is another Ammonite from this locality, wliich probably may be referred to the same species, as 

 it dilfers only in the tubercles at the margin of the periphery being more distinct. 

 " Fig, 2, Ammonites Nebrascensis ('!). Fox Hills, Nebraska. 

 " Figs, 3, and 3, a. Ammonites Nebrasrcnsis. Fox Hills, Nebraska, 



" Fig, 4, Scaphites nodosus (N. S.) Sage Creels, southern tributary of the Cheyenne, Nebraska, 



" Fig. 5. Ammonites lenticularis (N. S.) Fox Hills, Nebraska, associated with an Avicula. 



" Fig. 6. Ammonites opalus (N. S,) Great Bend of the Missouri River, associated with Inoceramns Cripsii. 



" Fig, 7. Ammonites Moreauensis (N, S.) Fox Hills of Nebraska, associated with Avicula, Tab, VIL, fig, lU, 



