406 



but not yet found in it, and doubtless some or all of these are to 

 be expected eventually. Such are: Oedipus platydactylus, Gas- 

 trotheca, Hyla leucophyllata, Phyllomedusa, Hypopachus, and 

 Gastrophryne, known from Costa Rica and from South America, 

 Bufo simus, Bufo veraguensis, Pleurodema, Hyla crepitans, from 

 western Panama and from South America, and Leptodactylus 

 melanonotus from western Panama and from Darien. 



Some 23 species are known definitely from western Panama 

 which have never been taken in our region. From eastern Pan- 

 ama only two such species are known, Hyla rosenbergi and Hy- 

 loxalus fuliginosus. Panama therefore may be divided into two 

 regions of amphibian distribution, the extreme west, and all the 

 rest, including the Canal Zone, to the Colombian border. Noth- 

 ing approaching a boundary can be set to these regions, and none 

 is to be expected, yet the difference between the amphibian 

 faunas of Almirante and of Barro Colorado Island is quite 

 marked. 



Within the region, Centrolene pulveratum, Agalychnis calcari- 

 fer, Hyla underwoodi, and Rana zeteki have been taken only on 

 the island. 



The island itself was, of course, originally a hill. The northern 

 side is quite steep, the middle and the eastern end are rather 

 flat, and the south and west sides are gently sloping. The 

 streams are all rather rapid, except the upper courses of some in 

 the center of the island, where rather large permanent pools may 

 be found, and swampy places in the rainy season. Such still 

 water is found between Zetek 3 and Armour 9 (habitat of Hyla 

 albomarginata) , and near the junction of Van Tyne-Chapman 

 (habitat of Agalychnis callidryas). Both these places also 

 shelter quite large caymans. 



The only other still water habitats are the inlets. Here Hyla 

 underwoodi and Hyla boulengeri may be found, wherever the 

 water is sufficiently sheltered from waves. Most of the other 

 amphibians seem able to use running water, or are terrestrial 

 in their breeding habits. 



I have tried to explain my belief that no great results may be 

 expected from further intensive collecting on the island. This 

 is especially confirmed by my finding the same creatures breeding 

 in July, 1930, that I found breeding in November and December, 



