Biifo terrestris 143 



The species bred from April 23-25. We heard them at 6o°-74°. On April 30 

 we had air 58° or less, in fact it went down to 50° or 5 1°. That night we heard 

 no toads from 5o°-58°. 



In 1922 whenever we had a chorus or considerable calling from July 2 to 

 August 18 downpours, rain or cloudy weather obtained. Our lowest tem- 

 peratures during the day were from 7o°-8i°. The minima for nearby stations 

 were from 62°-74°. The best choruses are at least 68°-74°. Rain is the 

 important factor. Toads will call at 60° or lower but humidity dictates 

 largely in the matter. 



MATING 



Male {From life, June 9, 1921). Line from front line of eyes almost to vent 

 pale gull gray or mineral gray. Black spots along dorsum: one pair near 

 cephalic edge of eye ; one pair from upper eyelid connected across the meson ; 

 one in the mid dorsum between tympana; a pair either side of middle between 

 the rear ends of tympana; a pair of small spots; a pair of large spots where 

 hump comes; a pair of small spots; a pair just ahead of vent — all black spots 

 of dorsum thinly encircled with chalcedony yellow. More or less broken 

 pale gull gray or mineral gray line from tympanum to groin. Below this a 

 prominent black area. Tubercles of back black or deep brown tipped. 

 Lighter areas on rear of hind legs sulphur yellow. Either side of vent a few 

 orange tubercles. Under parts pale smoke gray. Pectoral region, under parts 

 of hind legs, and sides with black spots. Lower jaw rim like belly color. 

 Throat deep mouse gray or dark mouse gray with widely spaced white dots. 

 Gives throat discolored appearance. Light area of dorsum of hind foot same 

 color as the rear of thighs. Very little rusty on front of thighs and groin. 

 Top of first two fingers with excrescences and slight line of such on edge of 

 third finger. Color of excrescences chocolate or better hay's maroon or 

 maroon. 



Female {From life, June 9, 1921). Lighter, larger. Practically no spots on 

 pectoral region. None on throat. Throat same color as belly. Practically 

 no rusty spots. Ground color of the dorsum more greenish olive. Some- 

 times at breeding season males and females may be alike in color, e.g., on 

 April 24, 1 92 1, several pairs were thus, several pairs reddish, one pair gray. 

 Most of pairs, however, were diverse. 



Structural differences. Some of the differences noted in the field are : 

 I. On April 24, 192 1, we observed the following: 



a. One male of a pair was about 3/5 of the female in size. 



b. One pair, both male and female, were reddish. Two more pairs 

 red. One pair grey. 



c. In some cases males and females alike in color but usually different. 



d. One pair with one hind leg of female freshly eaten off, possibly by 

 a turtle. 



e. The backs of the thumb and second finger of the male have ex- 

 crescences on the top and a slight excrescence on the inner edge of 

 the third finger. 



