THE SUBCLASS ANAPSIDA 221 



Procolophon Owen, Saurosternon Huxley, Thelegnathus Broom, 

 South Africa. Koiloskiosaurus Huene, Leptopleuron Owen {Teler- 

 peton Mantell), Sclerosaurus Meyer, Europe. 



Family Elginiidae. Skull triangular, broad behind, with long 

 horns in tabular region and numerous conical protuberances. Orbits 

 not elongate. Crowns of teeth denticulate. Intimate structure and 

 skeleton unknown. 



Elginia Newton, Scotland. 



2. ORDER EUNOTOSAURIA 



Primitive terrestrial reptiles with reduced dorsal vertebrae, ex- 

 panded ribs, and an incomplete carapace of dermal bones. 



The skull is doubtless wholly roofed over; the palatine is primitive, 

 with numerous teeth. Maxillae and premaxillae with a single row of 

 small teeth. External nares terminal. Vertebrae slender, notochor- 

 dal, with vestigial spines; capitular attachment of ribs on anterior 

 part of centrum, the second to ninth ribs with a vestigial tubercle, 

 progressively broadened, contiguous at their borders. Pectoral and 

 pelvic girdles primitive. Tail probably small. Femur slender, sig- 

 moidally curved; feet unknown. Dorsal region strongly convex, 

 covered with dermal ossifications, apparently in median and lateral 

 rows. 



This group at present is known by a single species, Eunotosaurus 

 africanus Seeley, from the Middle Permian of South Africa, repre- 

 sented by incomplete specimens which have recently been described 

 by Watson, from whom the above characters are taken. That the 

 genus is intermediate between the true Cotylosauria and the Che- 

 Ionia seems very probable, as Watson has urged. To locate it with 

 either order will require many modifications in their definitions. For 

 that reason it may be left in an independent position until further 

 discoveries furnish more details regarding the skull, limbs, and cara- 

 pace. The known characters ally it more closely with the Coty- 

 losauria than with the Chelonia. 



Middle Permian. Eunotosaurus Seeley, South Africa. 



