IHCYXODONTIA 



237 



consists of a sacrum composed of 5 confluent vertebrae, with 

 very broad iliac bones, and thick and strong ischial and pubic 

 bones. 



Some extinct plants allied to the Lepidodendron, with other 

 fossils, render it probable that the sandstones containing the 

 dicynodont reptiles were of the same geological age as those 

 that have revealed the remains of the Ehynchosaurs and 

 Labyrinthodonts in Europe. 



The generic name Dicynodon is from the Greek words sig- 

 nifying "two tusks or canine teeth." Four species of this 

 genus, having a rounded profile and less strongly ridged 

 maxillaries, have been demonstrated from the fossils trans- 

 mitted by Mr. Bain. 



Sp. Dicynodon laccrticcps, Ow.* — This species is founded 

 on a skull six inches in length, of which a reduced figure is 

 given in cut 73, where c shows the canine tusks. 



Sp. Dicynodon testudiceps, Ow. — In this species the skull, 

 and the facial part more particularly, is shorter than in D. 

 laccrticcps. 



Sp. Dicynodon strigiceps, Ow. — The shortening of the jaws 

 and blunting of the 

 muzzle are carried 

 to an extreme in this 

 species, in which the 

 nostrils are situated 

 almost beneath the 

 orbits. 



Sp. Dicynodon 



HcjriccpS, Ow."]" 111 Skull and tusks of Dicynodon lacerticefs. 



this species the length of the skull is 20 inches, its breadth 

 across the widest part of the zygomatic arches being ] 8 inches. 

 It differs from the D. laccrticcps not only in size, but in the 



* Trans. Geological Society, 2d series, vol. vii. (dis, two; Jcunodos, canine- 

 tooth.) f Trans. Geol. Soc, 2d series, vol. vii., p. 233. 



