JANUARY, 1902. PLACE MODES OF ACRIS GRYLLUS FOR MADISON, WIS. 
79 
The head, measured from the gular fold to tip of snout, varied 
from 8 m. m. to 11.7 m. m. ; reduced to per cent of total length 
the mode became 40 per cent to 42 per cent, with a range from 
34 per cent to 46 per cent. (See Poly. B.) 
The breadth of head was measured across posterior edge of 
the tympanums and was seriated in terms of head length and varied 
from 6.2 m. m.. to 8.8 m. m., and gave the mode of 78 per cent 
to 81 per cent, with a range from 63 per cent to 93 per cent. (See 
Poly. C.) 
The leg was measured from the granule beneath the vent to 
the tip of farthest projecting toe. It varied in length from 30 m. m. 
to 51 m. m. Divided by the total length the mode became 1.70 to 
1.74, with a range of from- 1.42 to 1.84. (See Poly. D.) 
The tibia is longer than the femur, and the femur somewhat 
longer than the foot. 
The foot is well developed. All the metatarsi are cleft to the 
base excepting the two outer ones which are united. The toes 
are webbed to the base of the disks, the membrane filling up 
most the space between them except on each side of the longest 
metatarsi where the membrane forms a narrow margin on the 
penultimate joint. On the exterior edge of the foot the membrane 
continues as a rudimentary one. (See Fig. III.) Beneath the 
articulations of the metatarsi are two large metatarsal tubercles, 
on the outer side of the tarsus are three or four well developed 
subarticular tubercles. The foot was measured and seriated in 
terms of leg length, from the large metatarsal tubercle to the tip 
of the longest toe. (See Fig. III. C-D.), and was found to vary 
from 8 m. m. to 14 m. m., thus giving a range from 40 per cent 
to 54 per cent, with a mode of 46 per cent to 48 per cent. (See 
Poly. F.) 
The projection of the second toe beyond the third (See Fig. 
Ill a-b), was found to vary from 2 m. m. to 5 m. m., with a range 
from 1.5 per cent to 6 per cent, giving a mode of 35 per cent to 
40 per cent. (See Poly. G.) It was also seriated in terms of 
length of foot and varied from 20 j>er cent to 47 per cent, with a 
mode of 32 per cent to 35 per cent. (See Poly. E.) 
The hands, like the feet, are well developed, though without 
webs. The fingers are provided with slightly enlarged convex 
disks, thus enabHng the creatures to climb upon smooth perpen- 
dicular surfaces. The disks are traversed by a slight groove. 
The inner finger is caudal to the rest, and is provided with a soft 
and prominent tubercle at its base. Separated from this tubercle 
by a narrow interval is another tubercle of about equal size. 
