28 E. C. CASE 



process on the lower end of the humerus would not permit this. 

 The tail would naturally seem to have been pretty long, if for no 

 other reason, than to preserve the symmetry of the animal ; 

 but the condition of the caudal vertebrae seems to negative such 

 a proposition. The vertebrae of all long-tailed forms gradually 

 decrease in size and the middle and posterior ones assume the 

 form of simple cylinders. In this specimen the vertebrae 

 decrease rapidly in size and the ones which are only half as 

 large as the first and second are as perfectly formed and as 

 specialized as any in the series. 



1. Baur and Case. "The History of the Pelycosauria, with a Description of the 

 Genus Dimeirodon." Trans. Am. Phil. Soc, N. S., Vol. XX (1899). 



2. E. D. Cope. "Systematic Catalogue of the Species of Vertebrates Found in 

 the Beds of Permian Epoch in North America, with Notes and Descriptions." Ibid., 

 Vol. XVI (1886). 



E. C. Case. 

 State Normal School, 

 Milwaukee, Wis. 



