738 W. F. CUMMINS 



visited the Permian beds and made a collection of the invertebrate 

 fossils. Part of these occurred at some of the same localities as those 

 from which Cope's vertebrate forms were taken. These inverte- 

 brates were afterward described by Dr. White (Amer. Nat., 1889, 

 p. 128, and United States Geological Survey, Bull. No. 77). 



Subsequently further collections of invertebrate fossils were made 

 by myself and other members of the Texas Survey. The cephalopods 

 were placed in the hands of Professor Alpheus Hyatt for determination 

 and description. His reports were published as parts of the Second 

 and Fourth Annual Reports of the Texas Geological Survey, 



The fossil flora was sent to Professors Fontaine and I. C. White 

 for their determination. A paper was published by them (Bulletin 

 of the Geological Society of America, Vol. HI, pp. 217, 218), giving 

 the results of their study. 



It is the purpose of this paper to describe more accurately the 

 various localities from which the fossils were taken, to indicate their 

 stratigraphic relation to the general section, and bring together a list 

 of the vertebrate forms' so far described from each locality, as nearly 

 as it is possible to give it from existing data. 



THE GENERAL SECTION 



The Permian deposits were described and separated into divisions 

 in the several reports of the Geological Survey of Texas. As a whole, 

 the formation comprises a series of sands and clays with interbedded 

 sandstones, limestones, and gypsum, lying conformably and with a 

 gentle westward dip upon the Coal Measures to the east and stretching 

 to the foot of the Staked Plains on the west. Three divisions are 

 recognized, the earliest and most easterly being the Wichita, followed 

 successively by the Clear Fork and Double Mountain. 



The Wichita division comprises a series of sandstones, sandy 

 shales, clays, and conglomerate, which passes gradually to the 

 southward into sandstones, clays, and limestone. In the earlier 

 reports, there being no apparent stratigraphic break between it and 

 the underlying Coal Measures and its materials being quite different 

 from the Wichita, these beds in the southern part of this field were 



I The lists sent me include batrachia and reptilia only. The fish will, therefore, 

 not be included in this. 



