276 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1923 



rather in contrast to the fluviatile or littoral facies represented by 

 the Texas Permian. 



The third great area for Permian vertebrates, the Dvina River, in 

 Poland, has not, so far as I know, been seriously exploited since the 

 work of Amalitzky, 20 years ago, nor has anything been added to 

 Fritsch's pioneer work in Bohemia. 



With all that has been done, we really know very little as yet of 

 the Permian land animals. The period was a most important and 

 critical one in the evolution of land life, for it witnessed the first 

 great expansion of land vertebrates, and the origin, probably, of 

 mammals, birds, and the principal orders of reptiles, including 

 dinosaurs. What we know best is the river-delta fauna of the Lower 

 Permian in Texas, a series of plains or desert faunae of Upper Per- 

 mian age in South Africa, and probably a similar facies in Poland ; 

 a small Permian swamp fauna in Bohemia, and a few items from other 

 regions. These must represent but a small proportion of the variety 

 and scope of land life of the Permian world. How imperfect a pic- 

 ture it gives may be judged by supposing that our knowledge 

 of the modern land vertebrates were similarly limited to the animals 

 of a South African desert, a Texas delta, and a swamp in central 

 Europe, with a few odds and ends from elsewhere. The zoogeo- 

 grapher would be bold indeed who propounded theories of distri- 

 bution and migration based on data so limited, and it is to be feared 

 that his conclusions would bear but little relation to the realities. 

 While it is thus necessary to emphasize the limitations of our knowl- 

 edge, it is but fair to say that it is vastly greater than it was a 

 decade or two ago. The number of genera on record is not so greatly 

 increased, but our systematic and anatomical acquaintance with the 

 characteristic types is more than doubled. 



TRIASSIC REPTILES AND AMPHIBIANS OF GERMANY 



Turning to the age of reptiles, we have in the Triassic the least 

 known chapter, so far as America is concerned, and very little has 

 been added to this chapter in the last decade. What little has been 

 accomplished in this direction is due to the energetic prospecting 

 of Doctor Case, and contains promising prospect for the future as 

 well as a few but very interesting additions to the Triassic faunae. 12 

 In Europe, however, the recent discoveries of Triassic dinosaurs 

 at Halberstadt and Trossingen in Germany and the discovery of a 

 complete skeleton of a South African Triassic dinosaur have given 

 an adequate basis for the study of these primitive dinosaurs and 

 appreciation of their real relations to the specialized dinosaurs of 

 the later geologic periods. Especially is the discovery by von Huene, 



"E. C. Case (1922) : Carnegie Inst. Pub. no. 321. • 



