INTRODUCTION 



The present work comprises a series of monographic studies, 

 together with briefer notes and descriptions, of new or little-known 

 amphibians and reptiles from the Permian deposits of Texas and 

 New Mexico. 



The material upon which these studies are based was, for the 

 most part, collected during recent years by field parties from the 

 University of Chicago under the charge of Mr. Paul Miller, assistant 

 curator of paleontology in the University of Chicago, or of myself. 

 The earlier collections of the University from Texas, made by Pro- 

 fessor Case, have been discussed by him in various papers, especially 

 in his monograph on the Pelycosauria, published by the Carnegie 

 Institution in 1908. In addition, I am permitted, by the kindness 

 of Professor Schuchert, to include herein the results of the investi- 

 gations by myself of the Permian collections from New Mexico 

 in the Yale Museum. In order that these results may have a 

 greater homogeneity than they would otherwise I repeat the descrip- 

 tion of the genus Limnoscelis published in the American Journal of 

 Science for May, 191 1, with additions, omissions, and corrections. 

 For the privilege of examining these important collections, so long 

 neglected, and of publishing the results of my studies, I would here 

 express my sincere thanks to Professor Schuchert. Farther on I 

 give some data regarding the type collections of Professor Marsh 

 from these New Mexico regions, and brief notes concerning the New 

 Mexico fauna, as represented in these collections, will be found in 

 the cited paper. I do not repeat them here, since a proposed further 

 exploration of these deposits by Professor Case in conjunction with 

 myself will doubtless furnish much more extensive and accurate 

 information concerning them and their fauna, which will be pub- 

 lished later by us. I may also say here that, in the future, it is 

 proposed by Professor Case and myself to publish the results of our 

 investigations of this important fauna, so long neglected, under 

 joint authorship. 



It is not my intention, however, to neglect the further exploration 



