THE BATRACHIA OF NORTH AMERICA. 77 



entirely, the ground ; mucous pores, as in the last ; belly with a median 

 dark or black baud; sometimes the yellow is shaded with olive: Nos. 

 4613, 4705, 3990, 4703, 4694 to 4699, 3955, 4078, 4079, 4066, 3982,' 5359, 

 4082, 3994, ISTo. 4020 might be assigned to either (3 or y. 



6 Ground olive, with numerous small brown spots; otherwise as 

 above; ISTo. 4693, and the type of ^. mac««ia^%w. 



e Brown above, yellowish below, otherwise as above; 3984&, 4702, 

 3992, 3955&, from most diverse localities. 



C Color as in y, the yellow leaving only inosculating lines of brown ; 

 no frontal, nasal, or mandibular series of mucous pores; one specimen, 

 No. 4698. 



So much as to the principle of ornamental variation. The following are 

 the forms resulting from unequal development of parts. The reader will 

 observe by the numbers how little they coincide with each other and 

 with the preceding. 



Type A. — Palatine teeth in a gentle arch, convex forwards, not extend- 

 iug between nares; the teeth (but not the ridge) interrupted inside the 

 series behind the nares. I^os. 4908 and 5359 (2 specimens); in all re- 

 spects fully grown, the former not more than half the size of the usual 

 type. Approach distantly A. irisrufptum Oop.e. 



Type B. — Palatine teeth forming a straight series on each side, meet- 

 ing at a more or less open angle between the nares. Most of the speci- 

 mens; ]S"os. 4702, 3992, 4705, 4613, 4065, 4040, 4698, 3900, 4703, 4694, 

 to 4699, 4081, 3955, 4079. Of these, the angle of the tooth series 

 does not extend beyond the anterior margin of the nares in twenty- 

 six specimens, of which one exhibits a small, undeveloped tongue, and 

 none have the stumps of the branchise remaining. In eleven specimens 

 the angle extends beyond this point (in 3990, and another approaching 

 an arch in form), and of these the tongue is small and larval in six, 

 and mone of these stumps of the brauchise remain; this last is of medium 

 size only, but Nos. 4693 and 3694 are large, the firs' very large; they add 

 the larval character of a short, deep tail. It is to be noted that these 

 specimens are from Minnesota and the borders of British America — re- 

 gions subject to great cold — to which cause we may with much proba- 

 bility assign their characters. Two individuals presenting the same 

 peculiarities are described under the head of A. tigrinum. 



Of two specimens from Chihuahua, fully developed, the teeth are of 

 the two types; of eight from California, one presents the second type 

 only ; it is otherwise fully developed. 



Type C. — The postnarial portion of the palatine series has nearly or 

 quite assumed its transverse position, while the median series remains 

 in its larval arch, extending more or less in advance of the nares. 

 Eight specimens, four of the largest size; 3955a, 4078, 4062, 4084; two 

 Museum of Philadelphia Academy, one type of A. maculatum Hall. Of 

 these, two have the small tongue and traces of branchise, while four ar^ 

 fully developed in these respects, 



