Theriodontia Diadectidce and Bolosauridce. 



61 



the Permian formation of North America. The premaxillary and Gallery, 

 maxillary teeth are of unequal size, as in Galesaurus, and there Jf ,:, 4 * 

 are two tusks near the extremity of the dentary bone. In Dime- N ^ ^e-case 

 trodon and Naosaurus the neural spines of the dorsal vertebrae Empedias. 

 have an extraordinary development ; the height of the spine in 

 one species being- more than twenty times the length of the 

 centrum. Prof. Cope concludes that these spines formed a kind 

 of elevated fin on the back, of which it is difficult to imagine 

 the use. In Naosaurus there were horizontal processes on the 

 spines of the vertebrae. This genus has also been recorded 

 from the Permian of Bohemia (see Fig. 79, p. 59.) 



Family DIADECTID^. In the DIADECTIDCE, represented by 

 'the genera Diadectes, Empedias, and Helodectes, the teeth are 

 transversely elongated, and are also divided by a median vertical 

 ridge, but both the inner and outer sides are equally low. They 

 are believed to have been herbivorous in diet. 



These genera are characteristic of the Permian of North 

 America; see Figs. 81 and 82, Empedias molaris (Cope). 



Family BOLOSAURIDJ;. Another closely related form, re- 

 ferred to the family of BOLOSAURIDCE, named Deuterosaurus, is 

 found in the Permian of Russia (Fig. 83). 



FIG. 82. Lateral and palatal view of posterior 

 tooth of Empedias molaris (Cope) ; Permian, 

 North America. 



FIG. 83. Lateral view of a premolar 

 of Deuterosaurus biarmicus (Eich- 

 wald), from the Upper Permian of 

 Russia. 



A tooth has been obtained from the Karoo beds of South 

 Africa closely resembling in general characters the anterior 

 teeth of Deuterosaurus. It has been made the type of the 

 genus Glaridodon. 



SUB-ORDEE 4. Pariasauria. 



In this sub-order are placed the remains of several other Wall-case, 



genera of Anomodonts. TJie-y include Pariasaurus, Anthodon, Tabte-case 



and Propappus, from tKe f riassic deposits of South Africa. No. 18. S6 ' 



' ^ THB. 



