The Green-frog, Ran a clamata Daudin. 75 



THE HATCHING PERIOD. 



Inasmuch as the eggs to Rana clamata are generally laid in the sum- 

 mer and deposited on the surface of the water, the air-temperatures play 

 a prominent role in determining the hatching period. This requires 3 to 

 6 days. We have numerous records of eggs hatching in 3 days when 

 the air-maxima averaged from 80 to 88 ; in 4 or 5 days when they averaged 

 80 to 70 degrees. The earliest hatching record for the species is May 

 16, 1911. Seldom have we seen eggs hatched before June 1. 



THE MATURE TADPOLE. 



Length of the body contained 1.5 to 2.1 times in the tail, average 1.75. 

 Width of the body in its own length, 1.25 to 1.7, average 1.47. Nostrils 

 decidedly nearer the eyes than the end of the snout. Eye distinctly 

 nearer the end of the snout than the spiracle. Distance between 

 nostrils 1.25 to 2.05 in interorbital space, average 1.6; in mouth 0.9 

 to 1.35, average 1.06. Spiracle sinistral, 1.35 to 1.8 times nearer the 

 base of the hind legs than the end of the snout. Anus dextral. Depth 

 of tail in its own length 2.5 to 3.7, average 3.1. Depth of the muscular 

 portion at the base of the tail 1.35 to 1.95 in the depth of the tail. 

 Mouth is contained 1.3 to 1.8 times in interorbital distance, average 1.5. 

 Greatest length, 84.8 mm. Greatest length of body, 27.8 mm. Greatest 

 length of tail, 57 mm. Greatest depth of tail, 16.6 mm. 



Coloration of body (Plate ix, Figs. IE, G) : Background of back very dark 

 and covered with very fine yellow spots, the whole consequently having 

 an olive-green color with numerous distinct dark spots. Belly deep 

 cream color without decided iridescence. The throat and sides are 

 mottled with dark green. A slight coppery iridescence on the venter is 

 more decided on the sides and on the tail. The tail appears green, 

 mottled with brown; it is covered with fine yellow spots like the back. 



Mouth-parts (Plate vm, Fig. 4) : Labium and its papilla? are strongly 

 and finely dotted with black, this being more pronounced than in Rana 

 catesbeiana. The labial mouth-parts of the latter when in situ are 

 narrower than those of the green-frog. The labial mouth-parts of the 

 bullfrog are contained in their width at least 2 times, while in the green- 

 frog the depth is never more than If in the width of the mouth-parts. 

 The second upper row of each side is very short, never one-quarter of 

 the upper fringe, as is frequent in Rana catesbeiana. There is never a 

 third upper row. The lower labial rows are as in the bullfrog. In the 

 lower rows of labial teeth R. clamata shows much less variation than 

 occurs in the more delicate similar rows of Rana catesbeiana. Seldom 

 do they depart from the normal arrangement. The greatest variation 

 occurred in the second upper row of either side. About half of the 

 specimens have the row on both sides ; many have the upper row missing 

 on one side ; and rarely they are absent on both sides, thus giving the 

 upper labium only one series of teeth. 



