From the INTRODUCTION. By aid of grants from the Carnegie Institution of Washington, the author has been for a number of years continuously at work upon the investigation of the vertebrate fauna of the Permo-Carboniferous beds of North America. The sudden and complete disappearance of this fauna (followed, after an interval represented by barren beds, by a highly specialized Upper Triassic fauna) has always been a tantalizing problem-the more so as the barren beds between the two widely different faunae are practically the same, in all the implications as to climate, mode of deposition, and terrestrial conditions, as the fossiliferous beds above and below. The interval of time represented by the barren beds is just the interval in which was developed the wonderful Permian and Triassic reptilian life of South Africa, Russia, and western Europe. A few very uncertain remains, briefly discussed in the section of this paper dealing with the Upper Triassic beds of western Texas, suggest the possibility that something of the Lower Triassic life of the Eastern Hemisphere reached North America. For these reasons the barren beds have been followed and searched with extreme care wherever they occur, but so far no trace of vertebrate life has been found in them. While engaged in such a search, the author learned of a small area in Crosby County, Texas, which has yielded a considerable amount of Upper Triassic vertebrate material, most of which is new. The present paper contains descriptions of this new and interesting fauna. The author takes this opportunity to thank the Carnegie Institution of Washington and its officers for the continued support which has made the work possible. Also, he wishes to acknowledge his obligation to Mr. Clifford Jones, manager of the Spur Farm Lands Company, and the other officers of the Swenson properties, for permission to go upon the lands under their control and for many acts of kindness and courtesy which rendered the task of collection much easier and contributed largely to the success of the work.