ORDER ANOMODONTIA. 



IO59 



opening. Cynodraco (fig. 980, b) also includes large forms with 

 greatly developed tusks, having compressed crowns with serrated 

 edges like those of the Mammalian genus Machcerodus ; the nares 

 being divided. Other genera from the Karoo system showing the 

 latter feature are Cynochampsa, Cynosuchus, and Scaloposaurus ; the 

 latter being one of the smallest known forms. Tigrisuchus, again, 

 is distinguished by its single nares ; while Gorgonops, of the same 

 deposits, has a narrow flattened skull, with the arrangement of the 

 nares different from that obtaining in all the preceding genera, and 



Fig. 980. — a, c, Anterior and lateral views of the skull of Lycosaurus ; B, Anterior view of the 

 skull of Cynodraco ; from the Karoo system of South Africa. Reduced, c indicates the tusk- 

 like (canine) teeth. (After Owen.) 



may indicate a distinct family. Deuterosaurus and other forms 

 from the Permian of Russia, which are included by Sir R. Owen in 

 the typical Theriodontia, are noticed below. 



Family Clepsydropid^e. — This name is applied by Professor 

 Cope to carnivorous Theriodontia, distinguished from the Gale- 

 sauridce either by the development of teeth on the palate, or by 

 the extraordinary character of their dorsal vertebrae, in which 

 large intercentra are typically present. All the genera are typically 

 from the reputed Permian deposits of North America. In the 

 type genus Clepsy drops the premaxillary and maxillary teeth are 

 of unequal size, and the dentary bone of the mandible has two 

 enlarged tusks near its extremity. Teeth are also borne on the 

 pterygoids ; and the neural spines of the dorsal vertebrae are not 

 excessively elongated. In Dimetrodon, the most remarkable char- 

 acter is the extraordinary development of the neural spines of the 

 dorsal vertebrae, which resembled those of Naosaurus (fig. 981), 



