42 ANGUIDA. 
Tue 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 Scinks, or Scincide, 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 Scincus, 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 Chalcides, and 
still more in Seps, 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 
