REPTILES OF LAKE SUPERIOR. 379 



The limbs are very slender ; the fingers very slim, and free for 

 their whole length. The carpus and tarsus are hardly broader than 

 the forearm and leg. The posterior extremities exceed the length 

 of the body by the length of the longest finger. All the fingers are 

 turned in one direction, bent outwards. The anterior limbs, half as 

 long as the posterior, have the two outer toes turned outwards, while 

 the two others are arched inwards. 



The upper surface of the head is smooth, as are also the back and 

 the legs ; but the sides are covered with minute cutaneous tubercles, 

 which extend over the whole lower surface of the body, where they 

 increase in size ; they extend, also, over the thigh and forearm ; the 

 lower jaw and extremities of the limbs, alone, being perfectly smooth 

 underneath. 



The color is of a bluish gray, irregularly speckled with small black 

 dots, which are partly oblong, partly circular, and very well circum- 

 scribed in their outlines, so that they show distinctly, notwithstanding 

 the slight difference in color. The lower surface is of a yellow- 

 ish white, dark upon the sides, lighter and purer under the head and 

 along the margin of the lower jaw. A very narrow white band 

 extends along the margin of the upper jaw, as far back as the inser- 

 tion of the arm, upon which it encroaches somewhat. 



Figs. 1, 2, represent the species of the natural size ; the first, in 

 the natural attitude of the animal ; the second, as seen from below. 

 Fig. 3 represents a tadpole, remarkable for the great length the tail 

 still preserves, the legs being already very far advanced in their 

 development. Whether they undergo their metamorphoses in one 

 season, or spend the first winter in an intermediate state between 

 their larval and adult form, has not been ascertained. 



RANA NIGRICANS, Agass. 

 PI. VI., figs. 4, 5. 



This species is intermediate, with reference to its size and the 

 development of its limbs, between R. clamitans and R. Tialecina. 

 It differs from both by its color, and by the form of its legs ; the hind 

 foot being more extensively palmate, and their membrane extending 



