236 PALEONTOLOGY 



FAM. — DlCYNODONTIA. 



A long ever-growing tusk in each maxillary bone ; pre-maxil- 

 laries connate, forming with the lower jaw a beak- 

 shaped mouth, probably sheathed with horn. 



Genus Dicykodon, Ow— In 1844 Mr. Andrew G. Bain, 

 who had been engaged in the construction of military roads 

 in the colony of the Cape of Good Hope, discovered, in the 

 tract of country extending northwards from the county of 

 Albany, about 450 miles east of Cape Town, several nodules 

 or lumps of a kind of sandstone, which, when broken, displayed 

 in most instances evidences of fossil bones, and usually of a 

 skull with two large projecting teeth. Accordingly these evi- 

 dences of ancient animal life in South Africa were first notified 

 to English geologists by Mr. Bain under the name of " Biden- 

 tals ;" and the specimens transmitted by him were submitted 

 to the writer for examination. The results of the comparisons 

 thereupon instituted went to show that there had formerly 

 existed in South Africa, and from geological evidence, probably, 

 in a great lake or inland sea, since converted into dry land, a 

 race of reptilian animals presenting in the construction of their 

 skull (tig. 73) characters of the crocodile, the tortoise, and the 

 lizard, coupled with the presence of a pair of huge sharp-pointed 

 tusks, growing downwards, one from each side of the upper 

 jaw, like the tusks of the mammalian morse (Trichecus). No 

 other kind of teeth were developed in these singular animals : 

 the lower jaw appears to have been armed, as in the tortoise, 

 by a trenchant sheath of horn. 



The vertebrae, by the hollowness of the co-adapted articular 

 surfaces, indicate those reptiles to have boon good swimmers, 

 and probably to have habitually existed in water : but the 

 construction of the bony passages of the nostrils proves that 

 they must have come to the surface to breath air. The pelvis 



