NO. 2211. GENERA DESMOQNATHUS AND LEUROGNATHUS—DUNN. 399 



Subfamily Dismognathinae. 



Key to the genera. 



a} Internal nares conspicuous, about as far apart as nostrils Desmognathus. 



a^ Internal nares very inconspicuous, twice as far apart as i\oaixi\&. Leurognathus. 



Genus DESMOGNATHUS Baird. 



1849. Desmognathus Baird, Journ. Acad. Nat. Sci. Philadelphia (n. s.), vol. 1, 



p. 82. 

 1854. Cylindrosoma (part) Dumeril and Bibron, Erp^tologde G^n^rale, vol. 9, 



p. 81. 

 1854. Plethodon (part) Dumeril and Bibron, Erp^tologie G^n^rale, vol. 9, p. 85, 

 1854. Amhystoma (part) Dumeril and Bibron, Erp6tologie G^n^rale, vol. 9, p. 105 . 

 1856. Plethodon (part) IIallowell, Proc. Acad. Nat. Sci. Philadelphia, pp. 6-11. 



Type-species. — Triturus fuscus Rafinesque. 



Diagnosis. — General characters of the Plethodon tidae. Tongue 

 attached, except by its lateral margins. Prefrontal bone wanting. 

 Premaxillaries united, embracing a fontanelle. Structure of internal 

 nares as in Spelerpes; that is, a notch in the vomer. 



Vertebrae opisthocoelous in the adult. Atlas without odontoid 

 process and with a transverse dorsal ridge on which the temporal 

 muscles originate. 



Occipital condyles on cyhndric pedestals. Vomerine teeth usually 

 present, but wanting in adult males of some species, A light line 

 from the eye to the angle of the jaw. 



There seems to be three groups of nearly equal value. These are: 

 1, quadramaculata; 2. monticola, fusca, auriculata, and hrimleyorum; 

 3. carolinensis and ochrophaea. 



Distribution. — The forms of Desmognathus occur all over the 

 eastern United States. Two specimens show that the genus is 

 represented in New Brunswick, There is also a record for the Gaspe 

 peninsula, but as this refers to larvae it is extremely doubtful. 

 Nash's records for D. fusca and D. nigra in southwest Ontario are 

 also doubtful. It can be afiirmed with considerable positiveness 

 that quadramaculata does not occur in Canada, and from the known 

 distribution oi fusca it seems scarcely probable that it either is found 

 in Ontario. 



Specimens and records are lacking from northwestern Ohio, north- 

 ern Indiana, northern Illinois, western Kentucky, western Ten- 

 nessee, and northern Mississippi, In Arkansas, hrimleyorum from 

 two neighboring localities is the only representative, Beyer (1900) 

 records /wsca as common all over Louisiana, I have seen specimens 

 from only the southeastern corner and these were auriculata. It is 

 very doubtful whether typical /wsca occurs in Louisiana. 



In mapping the ranges of the various forms one is struck by the 

 agreements with the maps in Transeau's paper on the Forest Centers 



