two outer fingers truncate, having
terminal transverse grooves, about twice width of narrowest
part of digit; digits of first and second fingers slightly
expanded; fingers from shortest to longest, 1-2-4-3, first
only slightly shorter than second; three palmar tubercles;
inner palmar tubercle about one third size of large median
tubercle; outer tubercle about one tenth size of large median
tubercle; four supernumerary palmar tubercles; tips of toes
slightly wider than narrowest part of digits; toes from
shortest to longest, 1-2-5-3-4, second only slightly shorter
than fifth; inner metatarsal tubercle about four times size
of small outer metatarsal tubercle; supernumerary tubercles
on foot small; no tarsal fold; heels touching when tibiae
adpressed to thighs; tibiotarsal articulation reaching eye
when leg adpressed to side of body.

Contrasting marbled pattern on back and top of head;
contrasting, mostly barred, pattern on limbs; ventral
surfaces whitish, lacking dark marks, but having minute dark
peppering; marbling of dorsal surfaces blackish and whitish
in preservative.

Vomerine teeth lacking; internal choanae lateral, partly
concealed by maxillaries; tongue smooth, elongate, shallowly
notched distally, free for about half its length; vocal sac
median; internal vocal slits large and near angle of jaw.

_Variation._--Twelve males closely resemble the holotype. Two
specimens from Pueblo Nuevo are soft and not well preserved.
The ranges of variation (means in parentheses) for the 13
males comprising the type series are: snout-vent length,
25.5-31.5 (27.9); width of head, 9.7-11.2 (10.5); diameter of
eye, 2.9-3.6 (3.2); horizontal diameter of tympanum, 1.1-1.8
(1.4); length of tibia, 11.1-13.1 (12.1); length of foot,
11.0-13.1 (12.1).

The pale ground color of the marbled pattern in most
specimens is least extensive on the back and arms, but most
extensive on the legs. The lumbar glands are slightly
elevated and conspicuous, and in KU 63328 are extremely
protuberant, or (KU 63330) evident on left side but flattened
and indistinct on right side. The back is rough having low,
scarcely elevated pustules, but becomes less rough anteriorly
and most of the top of head is smooth. The three specimens
from Pueblo Nuevo, Durango, differ slightly from the other
s