122 Kansas Academy of Science. 



THE SKULL AND EXTREMITIES OF DIPLOCAULUS. 



By S. W. WILLISTON, University of Chicago, Chicago, 111. 



IN 1877 1 Professor Cope described, from the reputed Permian of 

 Texas, some small vertebra? as of a salamander-like reptile un- 

 der the name Diplocaulus salamandroides. The type specimens, 

 now in the possession of the University of Chicago, were later 

 figured by Case."^ In 1882 Cope ^ recognized the same genus from 

 the Permian of Texas, and described more fully a species of a 

 much larger size under the name Z>. ')nagnicnrnix, which he now 

 referred to the Microsauria and to the family Diplocaulidae, which 

 he had previously proposed in a catalogue of the Permian verte- 

 brates as a member of the Pelycosauria.* He here describes for 

 the first time the characteristic zygosphene. In 1895 Cope,'' with 

 better material of D. magnicornis, gave a more complete descrip- 

 tion, correctly figuring the upper surface of the skull and the an- 

 terior part of the palate. He also described here briefly a third 

 species of the genus as D. limhatus. also from the Texas Permian, 

 and characterized chiefly by the posterior concavity of the cranium 

 and the greater protuberance of the quadratojugal posteriorly. 



In 1902 Broili^ published a preliminary description, with a 

 rather poor figure, of the same species, giving for the first time the 

 nearly complete structure of the palatal region. In the following 

 year JaekeP reproduced these figures and made some additional 

 observations in a discussion of Diceratosaurus . Again, in 1904 

 Broili^ published a more complete description of the same form, with 

 additional figures, and referred the genus to a new family, the 

 Diplocaulidae, under the misapprehension that Cope's name, given 

 in error of the real relationships of the animal, had become obso- 

 lete. In this latter paper Broili also described and named two ad- 

 ditional species, D. copei and D. pusilhis, the latter a very small 

 species, and doubtfully, I think, belonging in this genus. 



During the past year an expedition to the Permian of Texas from 

 the University of Chicago secured a number of excellent specimens 



1. Proc. Amer. Phil. Soc, 1877, p. 187. 



2. Journal of Geology. 1900, p. 710. pi. I, ff. 16a-176: pi. V, ff . 17a-17d. 

 ■',. Proc. Amer. Phil. Soc, 1882, p. 451. 



4. American Naturalist, XV, 1881, p. 162. 



5. Proc. Amer. Phil. Soc, 1895. p. 455. pi. IX. 



6. Centralblatt f. Mineralogie. 



7. Jahresbericht f. Mineralogie, 1903. 



8. Paleontographica, LI, 1904, pi. IV, ff. 4-15; pi. V, ff. 1-4; D. copei. p. 21, pi. Ill, ff. 1. 2; D. 

 pusillus, p. 24, pi. VI, ff. 1-4. 



