THE BATRACHIA OF NORTH AMERICA. 59 



the middle point of tbe axis. Younger specimens appear to have shorter 

 tails. 



There is considerable diversity in the carve of the transverse series 

 of palatine teeth. In nearly all more northern si)ecimens the central 

 row is formed of two arcs, concave anteriorly, more or less continuous 

 with the lateral, which are anterior and convex anteriorly. The two 

 central arcs are continuous at their inner ends, forming an inverted 

 angle on the axial line. Sometimes, however, as in most of the 

 specimens from Prairie Mer Eouge, this central angle is wanting, and 

 there is only a single arc or curve, concave anteriorly. In the type 

 specimen described this central row of teeth is nearly or quite straight 

 (which is quite apt to be the case in very large ones), while in one 

 specimen of ISTo. 4684 it is convex anteriorly. The transv^erse extent 

 of this middle line of teeth varies. Sometimes there is quite an interval 

 between it and the lateral, while in 3930, from IvTew York, they are con- 

 tinuous without appreciable interruption. 



There are no very great variations in the pattern of coloration. Gen- 

 erally the outer surface of the limbs is colored like the back, in which 

 case there are one or more large, rounded light siwts. The under parts 

 are generally dark bluish; the sprinkling of small white specks on the 

 sides and beneath varies considerably in prominence. The large dorsal 

 spots are always nearly circular, and vary in number, generally only one 

 series on each side. 



In living specimens from Carlisle, Pa., the iris is dark brown, without 

 metallic color, scarcely distinguishable from the pupil. The color of 

 the animal above is a deep anthracite black; beneath, dull livid. On 

 each side the dorsal line is a series of large, nearly'- circular, gamboge- 

 yellow spots, somewhat symmetrically disposed. These vary from 10 to 

 20 from head to tail, and sometimes are larger than the eye ; usually 

 about its size. On the sides and beneath are sparingly scattered small 

 bluish-white specks. The spots, both yellow and bluish-white, are some- 

 times found on the legs. 



In younger individuals the yellow spots are brighter and the black 

 ground deeper. — S. F. B. 



Professor Baird (Iconographic Encyclopaedia, 1851,) thus describes 

 the reproduction of this species : 



Early in April, or towards the end of March, large masses of gelati- 

 nous matter may be observed in ditches, pools of water, or mountain 

 streamlets, which on closer inspection will be found to consist of a num- 

 ber of hollow spheres, about a quarter of an inch in diameter, embedded 

 in or combined together by a i)erfectly transparent jelly. Within each 

 sphere is a dark object, a spheroidal yolk, which in the course of some 

 days becomes considerably elongated and exhibits signs of animation. 

 Omitting, vas unsuited to our pages at present, any account of the em- 

 bryonic development of the animal, we resume its history at the time 

 when its struggles have freed it from tlie shell of the sphere in which it 



