THE BATRACHIA OF NORTH AMERICA. 191 



There are no dermal appendages developed in this genus at the 

 breeding season. 

 I. Males with posterior lialf of the mandible concave and edentulous. 



Inferior lateral series of pores imperfect or wanting, superior none ; no tubercle 

 iu cauthus oculi ; tail mostly rounded ; fourteen costal plica3 ; a yellowish 



dorsal band ; belly immaculate ; size small D. oclirophcm. 



II. Males with mandibular alveolar margin continuous and completely toothed. 



Inferior lateral series of pores well developed, superior irregular or wanting ; a 

 tubercle iu cauthus oculi ; tail compressed, keeled, and finned; fourteen costal 



plicie ; above dark spotted, below marbled ; size medium D. fusca. 



Two well-developed lateral series of pores ; a marked tubercle iu the cauthus of 

 the eye; tail flattened, finned above, attenuate; twelve costal folds*; black 

 above and below ; size large !->• nigra. 



DESMOGNATHUS OCHROPH^A Cope. 



Proceed. Ac. Nat. Sci. Phila., 1859, 122. 



This small species bears a strong resemblance to the Spelerpcs hi- 

 Uneatus Green, and, apart from generic characters, may be known from 

 it by the rounded tail, the paler-colored abdomen, and the light bar 

 from the eye to the angle of the mouth. Its proportions are stouter 

 than in Plethoclon cinereus erythronotus, to which it also bears some re- 

 semblance. 



The costal folds are thirteen, but fourteen if that which is immedi- 

 ately above the groin be counted. The first falls immediately into the 

 axilla. This is the characteristic arrangement in D. fusca also, while iu 

 1). nigra the fold above the groin usually extends to it, and is the twelfth, 

 while that which corresponds to the first of the species before named 

 tails just in advance of the axilla. Though this is typical of D. nigra 

 occasionally another plica appears above the groin, and the twelfth is 

 >lightly in front of it. 



The pores in D. ochrophwa are very difiicult to observe. In a few 

 s[)ecimens I have seen a few of those of the lower series ; the upper I be- 

 lieve to be wanting. The gular fold is distinct, and another vertical fold 

 coiumences behind its extremity, and turning longitudinally, extends 

 more or less distinctly to the orbit. As in other species, the derm ad- 

 heres closely to the frontal bones and is more or less rugulose. The 

 head is oval, with rounded depressed muzzle; its greatest width en- 

 ters the length to the groin 5§ times. The commissure of the mouth is 

 t^lightly flexuose. 



The appressed limbs fail to meet by four intercostal spaces. The 

 inner digits of both feet are short but free, longer than in Plethodon 

 .species of similar size; the other digits are also longer and more dis- 

 tinct ; proportions, 1-4-2-3, 1-5-2-4-3; only three phalanges in longest 

 toes. The tail is quite slender, and only compressed at tip; in some 

 there is a keel above on tlie distal third, but never any dernjal fin. 



The vomerine teeth are very few and small when present; they are 

 often wanting. Their basal line is on a ridge, which is convex back- 



