SAURIANS. 501 



rudimentary limbs without any sub-division, or but one toe on 

 each foot. The only species is the C. anguina, of the Cape of 

 Good Hope, having the head covered with many side shields or 

 scales, and the cylindrical and elongated body covered with 

 elongate, keeled scales. 



V. Genus Saurophis, (Gr. Lizard-Serpent,) includes reptiles 

 with more highly developed extremities, each foot having four 

 toes. The only species known, is the S. tetradactylus, which 

 inhabits the southern part of Africa. 



The other genera of this sub-family have four- toes on each 

 foot, of these we can only refer to the genus. 



VI. Gerrhonotus, (Gr. shield-back,) of which there are eight 

 specie's, seven inhabiting Mexico, and one California. In these 

 reptiles, the thighs are destitute of the pores. They produce 

 their young alive; and in their habits, closely resemble the 

 Lizards. 



VII. Zonurus, (Gr. zone, belt; oura, tail,) is a genus in which 

 the limbs are four and robust; the feet each furnished with five 

 toes ; the tail is short, and the head triangular and flattened ; the 

 scales of the back and sides are square, in a close cross series. 



The CORDYLE LIZARD, Z. griseus, (Bibron,) or Cordylus 

 (Gr. a knotty club,) griseus, (Cuvier,) is an example of this 

 genus. It is a native of South Africa, where it is common. 



VIII. Tachydromus, (Gr. swift runner,) is a genus found in 

 Cochin China, China, Borneo, and Java, distinguished by having 

 keeled ventral shields ; and the throat with keeled scales. It 

 has, like the preceding, four lirnbs, but they are less robust ; five 

 toes, but three not fully developed, and a greatly elongated form. 



The TACHYDROME, T. sexlineatus, (Lat. six-lined,) receives 

 its specific name from having three lines extending longitudi- 

 nally on each side. 



Second sub-class. Glyptoderma, (Gr. carved -skin.) This 

 division nearly corresponds with the family Ampliisbaenida, of 

 some authors. The lateral furrow peculiar to these reptiles, is 

 faintly seen in the more typical Chalcides referred to above. Most 

 of the species have been classed by some with the Ophidia, which 

 they greatly resemble. From the latter, however, they are dis- 

 tinguished by their Saurian head and tongue; and by having 

 the vertebrae united by fibrous or thread-like cartilage. 



I. Genus Amphisbaena, DOUBLE WALKERS, so called from the 



strong resemblance between the front and hind extremities of the 



membranous body, the head, tail, and intermediate part being of 



- the same circumference. Appearing to have a tail at each end, 



they are supposed to be capable of progression in either direction. 



