BLIND-WORM. 43 
ones have wholly disappeared, and are found in a rudi- 
mentary state under the integument, the posterior ones 
constituting only small undivided processes. These also 
being removed, the Ophidian form of the present genus, 
and those of Tortrix, Typhlops, and others, with all the 
Amphisbenide, succeed, in which the bones of the shoul- 
der, the sternum, and the pelvis exist in a more or less 
rudimentary condition; and lead us towards the true 
Snakes, in which all these parts are lost excepting the 
rudiment of a posterior extremity, which in the Boa ap- 
pears externally in the form of a small horny hook, or 
holder, on each side of the vent. In the Serpents, the 
gape, too, has assumed its extreme power of extension, 
from the bones of the jaws and other parts of the face 
being separate ; and in most of them the scales, which in 
the former groups were similar on the upper and under 
parts of the body and tail, are small and imbricated above, 
whilst beneath they assume the form of broad transverse 
plates. Such is a very brief account of the beautiful 
gradations by which these reptiles pass from the true or 
typical Saurian to the Ophidian form; and although, per- 
haps, it would be more consistent with analogy to consider, 
with Merrem, the whole of the scaled Reptilia as consti- 
tuting one great order, yet the union of this interesting 
intermediate group, to which Mr. Gray has given the 
name Saurophidia from that relation, is a legitimate and 
important improvement upon the confusion in which they 
were left by Cuvier, who separated animals even of the 
same family, and placed some in his order “‘ Sawriens,” 
and others in his ‘* Ophidiens.” 
The structure of the common Slow-worm, then, necessa- 
rily removes it from the Snakes, to which, indeed, it bears 
a less close affinity than to some of the Saurians. This 
