Hyla fern or a lis 281 



Sept. 9. Heard at 6:20 p. m. 

 Sept. 12. Heard at 6:40 p. m. 

 Sept. 16. Several heard at night during heavy rain. 



In 192 1 in the last of April and first of May we had a good index of Hyla 

 femoralis activity. On April 24, April 25 and April 27 under influence of 

 65-75° temperatures and cloudy weather we heard a few, but on April 30 to 

 May 8 minima range from 40-54°, average 48 or below, maxima from 73-83, 

 average 77 for four stations around the swamp. The cold, brisk, clear weather 

 kept them inactive and none were calling. There was no or little rain before 

 May 1 1 when several Hyla femoralis began to call. The air felt like rain on 

 this date and for two weeks considerable rain fell. Hyla femoralis became 

 very active. Minima 60-70, maxima 73-89, average 82. It, therefore, was 

 not the maxima of April 30-May 8 or May 1 1-25 which played the prominent 

 part but the higher minima 60-70 (not 40-54 of April 30-May 8) and most 

 of all humidity were the important factors. These periods are typical and 

 no need of reviewing the whole period of 192 1 and 1922 in necessary. 



MATING 



Male (From life, June 5, 1921). Cephalic half of pectoral fold pale 

 vinaceous drab to darkish grayish brown, posterior half like the belly. Throat 

 darker than the belly. 



Female (From life, June 5, 1921). General color sorghum brown or deep 

 brownish drab or mars brown on back. Black spot between eyes. Another 

 spot with four points two behind and two ahead, the cephaHc ends above 

 tympanum. Two on either side of the middle of the back and one over the 

 crupper. Black or deep brown line from snout through nostril to eye narrow. 

 From eye through tympanum to groin where it breaks up into spots. Another 

 of same color on back of fore foot, fore arm, front of fore leg and over vent. 

 Below white line of the vent is a black one. Spots on rear of thighs orange to 

 chrome or light cadmium. One female with grayish white spots instead of 

 orange spots. Under parts white. Pectoral fold pure white to angle of the 

 mouth. Chin white with fine black spots. 



Iris ecru drab, drab gray, pale vinaceous drab with reticulation of black in it. 



Structural differences. In the Hylidae as Bufonidae we are accustomed to 

 saying that the throat of the female is not dark but more or less like the rest 

 of the venter. In many of the females of Hyla femoralis the throat is white 

 but sometimes the prominent white granulations have brown reticulations 

 around their bases. Occasionally only the tip of the granulations is white and 

 the general effect of the throat is very dark. 



The measurements of 134 adults, 70 males and 64 females yield the 

 following results: males range 24-37 mm., mode 31 mm., average 30 mm.; 

 females, range 23-40 mm., mode 36 mm., average 32 mm. A study of the 

 modes for these sexes reveals the following: The males and females start about 

 24 mm. The first mode for the males comes at 28 (9 specimens) mm. while 

 the first female mode is 30 (9 specimens). The second mode for the males is 



