1916 | Camp: Description of Bufo canorus 61 
MEASUREMENTS IN MILLIMETERS OF TyYPR SPECIMEN 
Total length TIN Cy iO Ot Berens sseeee eee eeee es 39.0 
Head length 18.9 Spread of hind foot —...... 22.8 
Head width _.. . 26.0 Length of parotoid ........... 12.2 
Hind leg - 82.0 Width of parotoid —........ 10.7 
DUG ah too 2 en csssmeeueesevccsevsaecavesesss 2OLO Interorbital space .............. 7.2 
Color (in alcohol). —Adult female, no. 5744, the type: All dorsal 
and lateral surfaces, including sides of head, rostrum and parotoids, 
thickly marbled with irregular but clearly defined, dark patches, each 
surrounded by a brilliant white line; many of the dark patches end 
abruptly at the mid-line, and do not cross it except in the anal region ; 
ground-eolor almost white, becoming brownish on the back and paro- 
toids; large tubercles in centers of dark patches tipped with brown; 
limbs mottled like rest of body; underparts clear white except for a 
few obscure dark specks; skin between large tubercles very smooth ; 
no trace of speeckling or of small dots between the dark blotches. This 
coloration is typical of all of the females, even the smallest. 
Adult male, no. 5747, typical in coloration of all the males in the 
series: Dorsad and laterad the body and limbs are covered evenly with 
minute dots of black on a uniform olive-green ground-color ; each dark 
speck surrounded by a narrow white ring; underparts grayish white 
with scattered dots of a larger size than those on the back. The skin 
is exceptionally smooth, and the larger tubercles and even the paro- 
toids are scarcely discernible. 
Remarks.—This toad is extraordinary in its pronounced sexual 
dimorphism. The striking black and white pattern of the female is 
entirely lost in most of the males, but a few of the latter show, by 
traces of blotching about the head and legs, that their speckled pattern 
is the result of a breaking up into smaller dots of the larger blotches 
of the female. In coloration the female of Bufo canorus bears some 
resemblance to the brighter patterns of Bufo boreas; the male phase 
has some counterpart in the latter species in the case of an occasional 
male of boreas, which assumes a dull green color and smooth skin 
during the breeding season. In the series of canorus the glandular 
development in the males is much less than in the females; in most 
of the males even the parotoids are not well developed, though their 
characteristic circular outline ean still be traced. 
The web of the hind foot is small; the spread of the hind foot is 
about 30 per cent of the total body-length, as in Bufo boreas halophilus. 
The sole is free from the asperities developed by toads of more arid 
