144 Universtiy of Kansas Geological Survey. 
correlation of these sandstones is the presence in the Avilla Hill 
sandstone of a considerable number of Lamellibranch shells. On 
account of the texture of the rock in which they are found, however, 
they are, in general, imperfectly preserved. A few of these speci- 
mens were referred to Mr. T. W. Stanton who reported as follows: 
“The specimens from the quartzitic sandstone of southern Comanche 
county, Kansas, apparently do not include any forms that can be 
considered characteristic of a known horizon. The most of them I 
cannot venture to identify even generically, as neither the hinge 
nor the surface characters are preserved. One specimen has on it 
an Avicula that may be the same as belviderensis Cragin. Another 
appears to be a Cucullaea and it also is possibly identical with the 
Kiowa species C. terminalis var. recedens Cragin. There can be no 
doubt that the quartzite is Cretaceous, but that is about all that 
could be said if its stratigraphical position were unknown.”! 
This sandstone, called the Cheyenne, is well exposed in several 
small ravines at the foot of the steep western side of the hill, where 
it varies from very hard to quite friable. The prevailing color is 
yellowish-brown, iron-stained to a very dark brown; but other 
colors are also conspicuous. Below, the Red-Beds are clearly shown 
upon which the Cheyenne rests. This stratum forms a conspicuous 
ledge on the northern slope of the hill five miles south of Avilla. At 
this place the sandstone is very hard, being decidedly quartzitic, of 
brownish color and contains numerous iron concretions. The rock 
contains a good many poorly preserved specimens of Lamellibranch 
shells, more numerous here than on the western side of the hill and 
it afforded the species studied by Mr. Stanton. 
This outcrop is a little east of the highway one half mile east of 
Avilla and five miles south. The readings of the barometer made 
the sandstone ledge at this place about 30 feet higher than on the 
western side of the hill. However, there was an interval of three 
hours between some of the readings so that the apparent difference 
in altitude is perhaps due to a variation in the instrument. Time 
did not permit to prove or disprove the above supposition by tracing 
the horizon around the side of the hill. 
Near the road the stratum is greatly broken, and large blocks 
1 Letter of Mr. T. W. Stanton, Dec. 3, 1896. 
