100 University of Kansas Geological Survey. 
ent divisions! As a result of this study Professor Cragin stated 
that “The above partial study of the Medicine river Cretaceous 
suffices to show something very like the fauna of the recently dis- 
covered Comanche series of Texas, which is said to be lower than 
the Dakota, or the lowest hitherto known American Cretaceous.’” 
Professor Hill referred to the above paper in his book on the 
“Neozoic Geology of Southwest Arkansas” stating that the rocks 
of the above section “Undoubtedly represent the Comanche series,” 
correlating No. 5 of Professor Cragin’s section, with the Fredricks- 
burg division of the Comanche, and No. 6 of Cragin probably as 
identical with the Trinity.’ 
In December of the same year Professor Cragin named the 
variegated sandstones at the base of the Cretaceous in the Medicine 
Lodge valley, the Cheyenne sandstone from the Cheyenne rock at 
Belvidere, Kansas.4 In this article Professor Cragin described the 
first fossil from the Cheyenne sandstone, part of a Cycad, for which 
ke proposed the name Cycadaidia mumta and doubtfully correlated 
the formation with the Trinity of Texas. The following year Pro- 
fessor Cragin published an article “On the Cheyenne sandstone and 
Neocomian shales of Kansas,’ in which he gives an excellent de- 
scription of the Cheyenne sandstone, stating its lithological charac- 
ters, thickness and distribution. The typical region of the develop- 
ment is given as Belvidere, where it attains a thickness of 40 feet 
and is reported “In parts of Barber, Pratt, Kiowa and Comanche 
counties.’”6 
In reference to its age Professor Cragin says: “‘While this sand- 
stone seems to be closely related to the Potomac and Tuscaloosa divi- 
sions of the Atlantic states, to the Trinity division of Texas and 
Arkansas, and to the Atlantosaurus beds of Wyoming and Colorado, 
it would be premature to assert positively, at this time, the precise 
identity of any two of these. Incomplete geographic and strati- 
eraphic data suggest a probability that the above-described sand- 
stone represents a portion of the Trinity division; but reference of 
1 Ibid., pp. 35-37. 
7 Aor) 19s Billo 
3 Annual Report Geological Survey Arkansas for 1888, Vol. II., p. 115, f. n. 
4 fF. W. Cragin, Bulletin Washburn College Laboratory Natural History, Vol. II, 
Dec., 1889, p. 65, Topeka. 
5 Ibid., Vol. II, Mar., 1890, pp. 69-81. 
6 Ibid., p. 69. 
