116 PROCEEDINGS OF THE ACADEMY OF 



a pad of crypts. The width of the head enters the length 5-66 times. The 

 vomerine teeth are often wanting, and when present, minute and few. Their 

 basis is a ridge which extends from behind the middle of the posterior nares, 

 across the palate with a posterior convexity. The parasphenoid patches are 

 small and not in contact ; they do not extend to opposite the middle of the 

 orbits. 



The median toes are elongate and as in D. ochrophasa; they fail to meet 

 by four interspaces when pressed to the side. The tail has a characteristic 

 form, which is invariable at all periods ; near the base the section is trigonal ; 

 the dorsal keel increases in elevation, and becomes a narrow fin posteriorly ; 

 the extremity is attenuated. Its length is just equal to that of the remainder 

 of the animal. 



There are two color varieties which blend together so as to indicate that no 

 higher value can be attached to them ; one of these is the Salamandra auricu- 

 lata of Holbrook. 



Above brown with gray and pink shades; sides and belly marbled, the 

 pale predominating ; no red spots on sides var. /usca. 



Above and sides black ; the latter with a series of small red spots ; a red 

 spot from eye to canthus of mouth present or absent ; belly marbled, the 

 dark predominating var. auriculata. 



The latter variety occurs only in the Southern States ; the tubercle of the 

 angle of the eye and the upper lateral pores are often better developed in it 

 than in var. fusca, therefore approaching D. n i g r a. It is, however, easily 

 distinguished from the latter. 



Sundry specimens lack the red spots, and others have paler bellies, resem- 

 bling thus the darker f u s c i. The size is the same. 



In the young of D. f u s c a there is a series of pinkish incompletely sepa- 

 rated alternating spots, in two series, covering the whole dorsal region ; tliey 

 are rarely so well distinguished or so bright as in the specimen of the same 

 which furnished the type of Holbrook's yS. quadrimaculata. The pink fades to 

 orange brown or ochre, and to pale brown with age, and at the fullest matu- 

 rity all are lost in a uniform blackish. 



Measurements, No. 6832. 



Inches. 



Length (axial) from snout to rictus oris -3 



" " " axilla. -71 



" " " groin 1-95 



'• " " end vent 2-3 



«' " " " tail 46 



" fore limb -43 



" " foot -15 



" hind limb...., -62 



" " foot -26 



Width sole do -16 



" head at rictus oris -375 



" body at middle -55 



Habitat, etc. — This species lives chiefly among the stones in the many 

 shallow rivulets and springs of the hilly and mountainous regions of the 

 country. It is not so partial to deeper and stiller waters as the Spelerpes 

 ruber, but prefers the rapid and shallow streamlets ; here it may be found 

 under every stone, or its delicate larva may be observed darting rapidly from 

 place to place, seeking concealment among mud and leaves. The D. f u s ca 

 is one of the most active and vigorous of our species. The peculiar structure 

 of the temporal muscle and its tendon, and of the occipital condyles, with the 

 strength of the bones of the front, enable it to burrow among stones and in 

 earth more readily than the species of other genera. When pursued it runs 



* [May, 



