402 FAUNA OF THE SOUTHERN ALLEGHANIES. 
traces in the form of an angle or swelling beneath the nos- 
tril on the lip, and sometimes as in the supposed species 
Spelerpes cirrigera, as a tentacle, or cirrus. Influenced by 
this consideration I referred Green's salamanders to his Sp. 
bilineatus.* 
In the course of collecting in the Alleghany region of 
Tennessee and North Carolina, I became satisfied of the pro- 
priety of this step. While in the recesses of a cave in the 
valley of Tennessee, in Jefferson county, I found a very fine 
specimen of Spelerpes longicauda of a red orange color, 
which had well developed tentacles on each side, precisely as 
in the cirriferous Sp. bilineata of Green. Subsequently in 
ascending the Black Mountains in Buncombe county, Nort 
Carolina, I found five specimens of the typical form of Sp. 
bilineata, of which three were tentaculate, and two were not. 
Finally, in a considerable number of the Sp. guttolineata, 
from the headwaters of the French Broad in North Carolina, 
one presented the same feature of well developed tentacles. 
This irregular preservation of a larval character, is o 
interest in connection with the theory of evolution. Should 
the presence of these tentacles be permanent in any species, 
it is not to be doubted that the character would be regarded 
as generic, and justly so. Its history would in that case be 
like the history of all other generic characters as represent- 
ing the undeveloped stage of another type, if not itself the 
ne plus ultra. Should it be constant in a color variety only 
of some species, and wanting in other varieties, and in other 
species, the first would become the type of another genus, 
whatever its claims to specific distinction might be. The 
latter would of course follow the former! If, however, the 
naturalist of the old school had any suspicion that the two 
forms may have had a common origin, he would ignore the 
distinctions. The proper course appears to me to recognize 
characters as definitive when they are constant, and discuss 
their history afterwards. 
* See Proceedings of the Academy of Natural Sciences, 1869. p. 107. 
