Cheyenne Sandstone of Kansas. — Cragin. 
29 
UPPER WEST BEAR CHEEK SECTION. 
No. 
Approx. 
Thickness 
IN FEET. 
Description. 
1 
Loup Fork Tertiary calcareous conglomerate. 
2 
40 
Dark brown to yellowish Dakota sandstone, containing 
meagre fragments of dicotyledonous leaves. 
3 
20—30 
Grayish white clay, interstratifled with horizontal and oblique 
beds of soft yellowish brown sandstone, varying to arenaceous 
clay more or less abundantly charged with clay-ironstone con- 
cretions, the latter locally so abundant that nearly the entire 
thickness of the horizon becomes one compact and massive 
ledge of clay-ironstone concretions. Fragments of G.pitcheri 
in the basal portion, whicD is, in fact, a transition to No. 4, are 
the only traces of fossils. 
k 
75 -90 
Blue and yellowish gray or brownish shale (the upper 20 or 
.30 feet usually yellowish or olive gray and the lower part blue, 
but the blue color often prevailing nearly or quite to the upper 
limit), with selenite crystals and thin plates of arenaceous 
slialy limestone in which (chiefly in the upper part of the 
series') occur Gnjjili;r<i pitcheri, Gryphsea vesicularis Lam., 
Trigonia emoryi, Ostrea franklini, Fholadomya sancta-sabx' 
Cardium hillanum, 0. kansasense Fdonearca vulgaris, and 
species of Anomia, Inpceramus, Cyprimeria, etc.. too obscure 
for specific identification. 
I have not been able to separate No. 4 of this .section into dis- 
tinct palajontologic horizons. Here, as elsewhere, the lowest and 
darkest portion of the dark horizon is void of fossils or nearly so. 
The prevailing pattern of the Gryphcea pitcheri of this locality 
is different from that of the Belvidere and Bine Cut mound dis- 
tricts. In that of the latter localities the tendency in the 
outline of the larger number of specimens is tow T ard an isosceles 
triangle ; in that of the Bear creek specimens what may be called 
the " bowl'" of the valve tends to a circular outline, from which 
the umbonal region is prominently produced. Specimens some- 
what approaching this type occur also on the upper part of 
Thompson creek in Kiowa county. Of Gryphcea vesicularis, I 
have collected one typical specimen only. This specimen, from 
near the top of No. 4 of the West Bear creek section, seems 
specifically identical with that figured by Prof. Whitfield in 
Monograph IN of the U. 8. Geological Survey* PI. IV. Fig. 1 ), 
and still more closely agrees with the form illustrated in Fig. 1, 
Plate IV of Marcou's Geology of North America under the name 
Gryphcea dilaiafa, var. tucumcarii. Certain forms of Gryphcea 
occurring on Bear creek lead me to suspect that it would he possi- 
ble to collect a series of forms connecting pitcheri with vesicularis. 
The Ostrea franklini of this locality is chiefly of a Large and 
thick variety, offering marked contrast to the thin and fragile 
