2 S.W. WILLISTON AND E. C. CASE 
these remains there are rocks of about nine hundred feet in thick- 
ness in the Lander region, and perhaps more in the southern region, 
which have been hitherto supposed to be utterly barren of all fossils, 
whether vertebrate or invertebrate; and there are at least three 
hundred and fifty feet immediately underlying strata of certain 
Upper Trias age which have never, in any place, yielded fossils. 
Everywhere characteristic of the uppermost beds, from Lander 
to New Mexico, Kansas, and Texas, are from five hundred to possibly 
a thousand feet, as estimated, of barren or almost barren measures, 
characterized by the lighter colors of the sandstones, often of 
aeolian origin, and more or less interspersed or capped with massive 
beds of gypsum, as at Lander, in Kansas, Texas, and New Mexico. 
The age of these upper beds throughout is assumed to be Triassic, 
but we know of no evidence whatever, save the color of the rocks, to 
differentiate the uppermost of them from the Jurassic,’ which lie in 
some places quite conformably above them. At Cafion City, 
Colo., the Hallopus beds, lying conformably immediately above 
the Red Beds, have been supposed by Marsh to be either of Lower 
Jurassic or Upper Triassic age, and the senior author from an 
examination of them agrees quite with his opinion. With this 
possible exception there are no fresh-water deposits in North 
America of Lower Jurassic age, the beds lying immediately above 
the Red Beds, whether conformably or not, being either the 
marine Jurassic (Sundance), or Morrison of uppermost Jurassic or 
lowermost Cretaceous age. 
At the base of these barren measures of Upper Trias or Jura- 
Trias age, in the Lander region, are thirty or more feet of massive 
sandstones, red, whitish, or variegated in color, underlain by pebbly 
conglomerates and clays, in which occur the remains of vertebrate 
fossils, if not in the sandstones themselves. Below these fossilif- 
erous beds, in this region, are nine hundred feet of red sandstones 
and clays, as recently accurately determined by Branson (im lit.) 
lying conformably, both with the overlying Upper Trias sandstones 
and the underlying beds of Pennsylvanian age (Embar beds, Bran- 
son).in which no fossils of any kind have ever been detected, though 
« These measures were referred by Cope to the Jurassic many years ago (G. M. 
Wheeler, Annual Report, 1875, pp. 78 fi.). 
