376 Frogs of the Okefinokee Swamp 



and Alabama the writer has chanced upon this species in full croaking season 

 in June and July. This species is reputed to lay small eggs in large masses on 

 or at the surface of the water in the early summer, and if this be true the habits 

 of this form are closely similar to those of the northern bullfrog." 



In 1923 (p. 34) the author asserts "And Rana grijlio has large films, one 

 by two and a half feet across much as does Rana catesbeiana.^' 



In 1924 (p. 379) A. A. Wright and I state the "egg mass (to be) over i 

 sq. ft. in area (144 to 288 sq. in. or 900 to 1800 sq. cm.) or 12 by 12 inches to 

 12 inches by 25 inches in diameter; usually in midpond; ..." Some Rana 

 grylios reach a size (almost as large as Rana catesbeiana and no doubt lay films 

 of about the same size as occur in the common bullfrog. 



Egg description (Field). The first fresh eggs secured June 8 were measured 

 roughly at night with a lantern light lest we lose the record. These records 

 were "vitellus 1.6 mm; inner envelope 3.6.; outer envelope 4.5-6 mm. These 

 will be revised tomorrow." On the morrow, the measurements were made as 

 follows: "vitellus i 55-1.85 mainly 1.6 mm.; a vitellus of 1.6 has vitelline 

 membrane 1.8 across it ; outer envelope 6 mm., sometimes 7 mm., some 4 mm. ; 

 inner envelope 3.6-4.0 mm.; vegetative pole white, animal pole black." 



No eggs were laid in camp by captives and our identification is presump- 

 tive but strongly supported. No R. catesbeiana are present. The only form 

 which might prove confusing are individual R. clamitans eggs. Whenever we 

 visited the places where the two were present R. grylio was in the middle of 

 the pond while R. clamitans was always in the wooded tangles at the edge of 

 the pond — Rana grylio in open pond, Rana clamitans in the most shaded parts 

 near the land's edge — distinctive habitats. 



In other field notes we have: outer envelope 3.8-4.0 mm.; 4.5-6 mm.; 

 4-6 or 7 mm.; inner envelope 2.8-3.2 mm.; 3.6 mm.; 3.6-4.0 mm.; vitellus, 

 1.8 mm.; 1.6 mm.; i. 55-1. 85 mm. After careful laboratory checks the measure- 

 ments when summarized are: 



Outer envelope 3.8-7 mm., merging more or less into the general glutinous 

 mass; inner envelope 2.8-4.0 mm.; mode 3.0 mm., average 3.45 mm.; vitellus, 

 i. 4-2.0 mm., mode, 1.8 mm., average 1.7 mm. Egg complement, 8,000 to 

 15,000. 



In the possession of inner envelope the egg of Rana grylio appears more 

 like that of Rana clamitans than that of Rana catesbeiana. 



Dangers. Sometimes one can see a spoiled mass very readily. On May 

 28, 192 1 "in a pond southwest of the boys' swimming hole found at the surface 

 of the water amongst pickerel weed (Pontederia) and hzard's tail (Sanrurus) 

 a mass of R. grylio eggs. I saw it some distance away because of the bluish 

 appearance of spoiled eggs. Sometimes a mass is revealed by a few eggs dried 

 or drying above the water on an iris or pickerel weed stem. Occasionally the 

 cypress ponds raise considerably after eggs are laid and some of the films may 

 be 3-8 inches below the surface. The most serious condition is where sudden 

 sinkings of level leave eggs attached far out of the water. Where most of the 

 eggs are laid, namely, on the prairies the loss probably is not so serious as in 

 isolated habitats. I know of no animal enemies which feed on the eggs. 



