28 Frogs of the Okefinokee Swamp 



have been from spirit specimens. Furthermore the date of the description is 

 given. A July description might be quite different from a March or an April 

 one in color tones. True, we could not attempt to catalogue all the variations 

 in color and these descriptions are only as representative as the season and 

 circumstances would permit. In almost every species there were pronounced 

 differences between the males and females of a species. 



STRUCTURAL DIFFERENCES 



In all the frogs (Rana) the enlarged thumb is the best criterion of maleness. 

 None of these Ranas of Okefinokee have two excrescences on the male's thumb 

 as in some of the Pacific coast species of Rana, and none seem to have the webs 

 of the hind feet as in some northwestern and northern species. In the southern 

 meadow frog and gopher frog we have not the distinctive differences, of 

 tympana found in the green frog, carpenter frog, mink frog, Heckscher's frog, 

 southern bullfrog or common bullfrog. There may be more yellowish tints in 

 the throats of those five in the males than in the females. 



In the Hylidae of the Okefinokee region the series may be separated by 

 the different color on chin and throat except possibly at times in the pigmy 

 Pseudacris ocularis. In the same way it is not always easy to separate a male 

 narrow-mouthed frog from a female of the same species. In the solitary 

 spade-foots the throats, excrescences on fingers and coloration of the back 

 generally assist. In the toads the customary differences more or less obtain. 



THE CUSTOMARY AMPLEXATION 



(PI. IV, Figs. 1-4; PI. V) 



In the two toads (Bufonidae) oak toad and southern toad the embrace is 

 axillary or at times supra-axillary with the first two fingers folded back. In 

 the nine species of tree frogs ( Hylidae) herein considered, namely, the little 

 chorus frog, black swamp cricket frog, cricket-frog, southern tree frog, pine 

 woods tree frog, Anderson tree frog, green tree frog, common tree toad, and 

 Florida tree frog, the embrace is axillary or supra-axillary. In the narrow- 

 mouthed toad (Brevicipitidae) it is axillary. In the spade-foot (Scaphio- 

 podidae) it is inguinal. In the eight species of frog (Ranidae) considered, it is 

 pectoral. These eight are, southern meadow frog, gopher frog, carpenter 

 frog, green frog, mink frog, Heckscher's frog, southern bullfrog, and bullfrog. 



CROSS EMBRACES 



(PI. IV, Fig. 7) 



In our study of the Salientia of Ithaca we were in the process several years 

 and had ample material. But in a trip to other parts one's material is care- 

 fully isolated to insure normal life history notes in the short period at hand. 

 In these trips little attempt or opportunity was given individuals for cross 

 embraces in the camp laboratory. Some of the records given were field 

 observations and casual notes. 



