GIRTY, THE GU ADALU PI AN FAUNA 
147 
in the fauna which made itself felt in the limestone at Cloudcroft or possibly 
earlier. Still another change of conditions, inaugurated apparently further 
south, produced the remarkable Guadalupian faunas, organic life in the Sacra¬ 
mento Mountains apparently remaining nearly static. Static conditions seem 
also to have prevailed in the Mississippi Valley 1 through all this period, and 
beyond into the “Permian,” allowing but slight and gradual faunal develop¬ 
ments which did not at any time assume a facies resembling the higher faunas 
of the trans-Pecos. Later than the Guadalupian and later also than the ex¬ 
tinguished faunas of the Kansas section, came those of the higher “Red 
Beds” of Oklahoma (Whitehorse and Quartermaster). Although my knowl¬ 
edge of the last mentioned faunas and their occurrence is largely second hand, 
they seem to present such marked differences from the Kansas Permian that 
it would be well, it seems to me, to consider carefully whether it is appropriate 
to include them in the same group. These faunal modifications, which are 
almost without known parallel in the Paleozoic, are certainly, so far at all 
events as the Guadalupe and Sacramento mountains are concerned, independ¬ 
ent of the direct influence of barriers and are apparently to be interpreted 
upon the basis of environmental influences. At present the area in cpiestion 
seems to offer a field for research in the matter of faunal modifications of 
the greatest interest and promise. 
1 Dr. Beede states that an intermingling of the faunas of the two areas was impossible to a 
considerable extent after about the horizon of the Topeka limestone (Jour. Geol., vol. 17, p. 679. 
1909.) 
