PALEONTOLOGY. 331 



PALEONTOLOGY. 



Case, E. C, University of Michigan, Ann Arbor, Michigan. Study of the 

 vertebrate fauna and paleogeography of North America in the Permian 

 period, with especial reference to world relations. (For previous reports 

 see Year Books Nos. 2, 4, 8-15.) 



Work under this grant has been largely directed during the last year 

 to the collection and correlation of data bearing upon the stratigraphy, 

 climatology, life, and paleogeography of the late Paleozoic, especially in 

 North America. Much important material has been gathered, both 

 by original investigation and by the compilation of the results of other 

 workers, but the number of publications it is necessary to consult is so 

 great and the area to be covered so large that much remains to be done, 

 and it is only possible to report satisfactory progress. While material 

 has been collected which would permit the pubhcation of numerous 

 short preliminary papers, the outlook upon the subject and the con- 

 sequent method of treatment is developing so rapidly that it has seemed 

 best to retain the material for publication in a single volume. 



Urgent necessity in other lines of work made it impossible to under- 

 take a field expedition in the summer of 1917. 



Hay, Oliver P., U. S. National Museum, Washington, D. C. Associate in 

 Paleontology. (For previous reports see Year Books Nos. 11-15.) 



During the past year Dr. Hay has been engaged in further study of 

 Pleistocene vertebrate materials, in trying to reach some general con- 

 clusions, and in preparing the manuscript of his report. Especial 

 attention has been given to the geology and the paleontology of the 

 Pleistocene of the States occupying the region of the Great Plains and 

 around the Gulf of Mexico. In nearly all of these States there are 

 found, in considerable abundance, fossil remains of miammals which 

 belonged evidently to the early part of the Pleistocene. In Texas there 

 is a low plain, about 90 miles wide next to Louisiana but considerably 

 narrower as the Rio Grande is approached, which is occupied by the 

 Pleistocene formations known as the Lissie and the Beaumont. The 

 opinion has been expressed by geologists that the materials of these 

 formations were brought down by the rivers and spread out on the 

 sea-bottom at their mouths. Under such cu-cumstances one might 

 expect to find abundant fossil marine mollusks and some bones of ma- 

 rine vertebrates. On the contrary, at many places and at various 

 depths, down to the coast, have been found remains of mastodons, 

 elephants, and horses, some of these belonging evidently to the early 

 part of the Pleistocene. During its formation the plain must have 

 been sufficiently above water to permit the presence of a dry-land fauna. 

 The writer believes that the greater part of this plain is older geo- 

 logically than has been supposed. 



The same early Pleistocene fauna is found to continue around the 

 Gulf into Florida, with some interruption apparently in Louisiana. 



