42 ANGUIDjE. 



The group to which the genus Anguis belongs is one 

 of the most interesting in its relations of all the forms of 

 Reptilia. Under external characters considerably differ- 

 ing from each other, — some possessing the limbs and loco- 

 motion of true Lizards, and others wholly devoid of 

 external members and moving like true Serpents, — there 

 are in Mr. Gray's order Saurophidia many points of 

 mutual affinity which prevent the possibility of separating 

 them from each other. From the well-known family of 

 the Stinks, or Scincidte, with their true legs and five-toed 

 feet, down to the present species and its immediate con- 

 geners, every possible gradation is to be found in the 

 development of the anterior and posterior extremities. 

 Agreeing, as they all do, in the Saurian character of the 

 structure of the head, the consolidation of the bones of 

 the cranium and jaws, and the narrow and confined gape, 

 so different from these parts in the true Serpents, they 

 yet approach the latter in the comparative length of the 

 bodies and in the gradual diminution and ultimate dis- 

 appearance of the extremities. In the genus Scincas, for 

 instance, the limbs are already less robust than those of 

 the true Saurians ; the two pairs are also more distant 

 from each other, in consequence of the greater comparative 

 elongation of the body. There are as yet five perfect toes 

 on each foot, which, however, are shorter and more even 

 in their relative proportions than in the Lizards. These 

 deviations become increased in the genus C/ialcides, and 

 still more in Sejis, which has a very elongated body, the 

 limbs extremely small, and the toes only four or three 

 on each foot. In Monodactylus a further reduction takes 

 place in the development of the limbs, which have dwin- 

 dled to a mere little undivided finger ; they are still, how- 

 ever, four in number ; but in the genus Bipes the anterior 



