PALEONTOLOGY. 395 



PALEONTOLOGY. 



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

 vertebrate fauna and palceogeography of North America in the Permian 

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

 Year Books Nos. 2, 4, 8-20.) 



A report on the preliminary work upon the discoveries made in the upper 

 Triassic of western Texas was printed in the Year Book for 1921. The work 

 has been completed and the final report has been issued entitled "New 

 Reptiles and Stegocephalians from the Upper Triassic of Texas." 



During the summer of 1921, exploration for the discovery of other fossil- 

 iferous beds in the upper Triassic was carried out on both sides of the Staked 

 Plains with but little success. However, relations were established with 

 parties interested in the local areas, and it is hoped that new localities may be 

 discovered and reported. 



With the reestablishment of the possibility of scientific work abroad, work 

 upon the relations of the Permian deposits of North America to the Permian 

 deposits in other parts of the world will be resumed. Dr. Case sailed for 

 Europe about the middle of July 1922 and will remain abroad for fourteen 

 months, examining the Permian deposits and the collections in the museums 

 in Europe, South Africa, Australia, and India. 



Hay, Oliver P., U. S. National Museum, Washington, District of Columbia. 

 Report on work done on the Pleistocene epoch and its vertebrate fossils. 

 (For previous reports see Year Books Nos. 11-20.) 



During some months following his last report the writer was engaged in 

 studying the Pleistocene geology of the Great Basin region of Utah and Nevada 

 and the Pleistocene vertebrates there discovered. Essential to the under- 

 standing of the problems there presented are G. K. Gilbert's Lake Bonneville 

 (Monogr. U. S. Geol. Surv., Vol I) and I. C. Russell's Geological History of 

 Lake Lahontan (Monogr. U. S. Geol. Surv., Vol. XI). Important aid is fur- 

 nished by Dr. Wallace W. Atwood's paper on his investigations on the 

 Wasatch Mountains (Profess. Pap. U. S. Geol. Surv. No. 61) and Dr. John C. 

 Merriam's report on vertebrate fossils found at Astor Pass, Nevada (Bull. 

 Dept, Geol. Univ. Calif., Vol. VIII, pp. 377-382). From a study of these and 

 other authorities the writer concludes that the deposits of white marls (the 

 Upper Bonneville) at Lake Bonneville and Russell's Upper Lacustral clays 

 at Lake Lahontan belong approximately to the Aftonian stage, while the 

 yellow clays at Lake Bonneville and the Lower Lacustral clays at Lake 

 Lahontan are to be referred to the Nebraskan stage. Unfortunately the num- 

 ber of species of fossil vertebrates discovered in the Lake Bonneville deposits 

 is very few and of little value. Those found in the Lake Lahontan region, 

 horses, camels, and an extinct tiger, throw distinct light on the age of the 

 beds, but here again the material is scanty. 



The writer has also devoted some time to the study of problems connected 

 with the Pleistocene geology of Iowa, where all of the glacial stages are well 

 represented and likewise most of the interglacial stages, if not all. 



Since the beginning of 1922 the writer has been occupied mostly in revising 

 the manuscript and seeing through the press the "The Pleistocene of North 

 America and its vertebrate animals." It will form publication No. 322 of the 

 Carnegie Institution of Washington. 



