Rana clamitans 361 



In 192 1 some of the first eggs of July 5 were as follows: Vitellus of one 

 1.4 mm., two more each 1.6 mm.; vitelline membrane of one vitellus 1.6 mm. 

 is 2.2 mm. in diameter, the vitelline membrane may be quite remote from the 

 vitellus, sometimes as development proceeds the membrane shows more dis- 

 tinct than the inner envelope; inner envelope usually pyriform, eUiptic or 

 sometimes circular, inner envelopes of 2.6, 2.8, 3.0, 3.2, 3.4 mm., most of them 

 at least 3.0 mm. or more. The outer envelope is seldom distinct if present 

 but probably becomes a part of the film or jelly matrix of the mass. Later 

 the same day we make this notation in regard to some other R. clamitans 

 eggs: "These eggs are fresh. Others described are not so fresh. The inner 

 envelope is round, 3.2-3.6 mm.; the vitelli 1.2, 1.2, 1.3, 1.4 mm.; vitellus 

 black and white." 



Dangers. None of the Ranas of the swamp lay in such precarious places 

 as the green frog. It chooses the edges where water levels change most 

 quickly. I beheve in my experience I have found proportionately more 

 spoiled R. clamitans masses than with any other species. On July 5, 1922, in 

 one pool the water reached two inches in depth and the eggs were about at the 

 hatching stage. Many a time we found the green frog tadpoles in cut off 

 shallow pools of cypress ponds. In our own pond (at Ithaca) we find that the 

 frogs, particularly males and sometimes females, are easier of capture at 

 breeding time. The toll of frogs from water snakes (Natrix s. sipedon) is 

 considerable. We have seen water snakes seize more green frogs than any 

 other species of frog and have often made these snakes release their quarry. 



HATCHING PERIOD 

 In 19 1 2 one mass of June q hatched in three days. 



MATURE TADPOLE 



Color description from life ( Non Ridgway) . 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. 



General appearance. Tadpole large, not deep bodied. Tail fairly elon- 

 gate, tip acute. Dorsal crest not so wide as musculature, extending forward 

 on body sHghtly ahead of the vertical of the ends of the hind legs. Spiracle 

 sinistral, just visible from dorsal aspect, directed obliquely upwards and back- 

 wards. Spiracle below lateral axis. Spiracular opening elliptical and plainly 

 visible as such. Muciferous crypts very distinct in life, indistinct in most 

 preserved specimens. Eye on or above lateral axis and near lateral outHne 

 in dorsal aspect than mid dorsal line. Anus dextral, opening on level with 

 edge of ventral crest. 



Mouth parts. Edge of upper labium fringed with teeth and about equal 

 to upper horny beak in length as in R. grylio. In either corner, beneath this 



