404 



Date 



Inches 



Date 



Inches 



Date 



Inches 



Dec. 11 



0.77 



July 



10 



0.00 



July 



20 



0.02 



12 



0.01 





11 



0.74 





21 



0.00 



13 



0.00 





12 



0.91 





22 



0.00 



14 



0.00 





13 



0.15 





23 



0.47 



16 



0.00 





14 



0.08 





24 



0.50 



16 



0.00 





15 



1.03 





25 



0.11 



17 



0.00 





16 



0.00 





26 



0.11 



18 



0.00 





17 



0.30 





27 



0.01 



19 



0.42 





18 



0.46 





28 



0.04 



20 



0.04 





19 



0.41 





29 



0.00 



21 



0.12 









Aug. 



30 



31 



, 1 



0.00 

 0.00 

 0.01 



November, 1928, had an excess of 2.5 inches, December, 1928, 

 had an excess of 2.99 inches, and July, 1930, had a deficiency of 

 4.32 inches on a five year average. 



The amphibian fauna of Barro Colorado Island, at the time of 

 writing, consists of one caecilian, two salamanders, and 30 frogs, 

 a total of 33 species. Twelve additional frogs are known to 

 occur in the limits of the Canal Zone. The Provinces of Panama 

 and Colon, which surround the Zone, harbor an additional sala- 

 mander and nine more frogs, and bring the total count up to 55 

 species. 



Our knowledge of the amphibian fauna is by no means com- 

 plete, but it is fairly clear that, as far as the Canal Zone and 

 Barro Colorado Island are concerned, no very material increment 

 is to be expected. This statement calls for further elucidation, 

 and indeed no guide to the amphibians of Barro Colorado and 

 the Canal Zone would be complete without some consideration 

 of the faunistic and ecological relations of the region. 



Amphibian distribution in the tropics is largely a matter of 

 rainfall (total and seasonal) and altitude. Except for very high 

 altitudes (which do not enter our consideration) temperature 

 plays little part, and the effect of mountains of low altitude is 

 largely their effect on rainfall. 



The whole region of the Zone is one in which there are two 

 marked seasons, a rainy season from May to November, and a 

 dry from December to April. This distribution of rainfall holds 

 true for Balboa, Barro Colorado, Colon, Chiriqui, and Garachine 



