THE BATRACHIA OF NORTH AMERICA. 51 



Teeth as in the last; width of head iu siuall specimeus, 3.5 to groiu; iu 

 adults, 4.5 times; a stroug dorsal groove aud longer tail ; blackish 

 above, with a series of rouud yellow spots ou each side of the back. 



A. puHclatiivi. 



Median series of teeth convex, advancing beyond posterior margin nares ; 



width of head much less than one-fourth length to groin ; tail short, 



no dorsal groove ; lead-colored, with an inferior lateral aud usually 



superior series of small irregular yellowish gray spots. . A. conspersum. 



I3l3 Two distinct plantar tubercles; 



P.Iediau series of teeth straight, nearly divided; external nares much 

 closer together than internal; width of head more than one-fourth 

 length to groin ; muzzle very short ; tail much compressed ; black- 

 ish above, with large, irregular, yellow spots, confluent on sides ; be- 

 low yellow A. hicolor. 



aa Vomerine series four. 



Teeth in four series, which form an obtuse angle directed forwards; width 



of head, 3.6 times in length to groin; length fiom muzzle to axilla 



equal length from axilla to groiu ; tail nearly as long as head and 



body; dark brown, with a dark brown band ou side ...A. copeanum. 



i.\ Costal grooves, twelve; 



a Larger species, with two distinct plantar, tubercles and mucous pores ou the 



side of the muzzle. 



(i No canthus rostralis ; tail shorter than head aud body ; chin not projecting. 



Vomeropalatine tooth series with the median portion presenting a very 



obtuse angle forwards, rarely straight, sometimes, with the lateral 



portions separated ; brown, with large yellow spots of larger or 



smaller size , A. tujrin urn. 



Muzzle broad obtuse; dark brown, with vertical yellow spots on sides; 

 teeth in four distinct series, in a nearly transverse line. 



A. trisr upturn. 

 J3i3 Canthus rostralis distinct ; chin projecting. 



External nares nearer together than internal ; muzzleobtuse ; head small, 

 width 5 times to groin ; front convex ; tail longer than head and 

 body ; vomerine teeth in one series, slightly convex forwards ; yel- 

 low, with irregular brown bauds above A. xiplnas. 



aa Smaller species; the mucous i^ores not extending beyond the orbits; teeth 

 in three series; no, or one indistinct plantar tubercles. . 

 External and internal nares equidistant ; vomerine series nearly trans- 

 verse; width of head, 4.5 to 6 times in length to groin ; length of 

 eye, 1.75 to 2.5 times in width between anterior canthus of same ; 

 lead coloi-ed to brown or black, with or without pale or distinct 



lateral spots A. Jefferson ianmn. 



Nares equidistant ; width of head, 5 times to groiu ; muzzle contracted ; 

 length of eye, entering 1.66 times in width between canthus of same, 

 once to nostril; median dental series augulated forwards; digits 

 long; brown or lead colored, usually a broad gray band on vertebral 

 line of tail and body expauding on occiput ; sides, dark reddish-brown. 



A. viacrodactylum. 



Muzzle wide ; width of head entering length to groiu 4 times; tail long 



as head and body to groin ; digits short ; black, upper surfaces bright 



yellow A. epixanthum. 



These species are distributed as follows : One, the A. persimile Grray, 

 is said to be an inhabitant of the mountaiu regions of Siam. The others 

 are all North American. One species only, the A. tigrinum^ extends 



