96 Evermann and Goldsborough — Fishes from Canal Zone. 



3. Tahernilla. This is a small town in Atlantic drainage, about 

 midway between the Atlantic and Pacific coasts. The speci- 

 mens obtained here are all from a small stream not more than 

 2 feet wide rising in a small spring which was full of leaves and 

 small fishes. When a quantity of water was dipped up from 

 the spring there was quite as much leaves and fishes as water. 

 Mosquito larvse were abundant and seemed to be living ami- 

 cably with the fishes; the fish did not seem to be eating the 

 larva3 or the mosquitoes. Collections were made by Mr. Busck 

 at this place. 



The collections by Mr. Jennings were made at Tabernilla in 

 January and July, at Gorgona and Paraiso in February, and at 

 Caldera Island, Porto Bello Bay, in January, March, and April, 

 all in 1908. 



The specimens of Gamhusia episcopi, Poecilia sphenops, and 

 Agonostomus monticola from Caldera Island were taken from a 

 small mountain brook. 



The construction of the Panama Canal is a matter of great 

 importance to students of the geographic distribution of animals 

 and plants. The completion of the canal will establish a per- 

 manent waterway and means of communication between the 

 Atlantic and Pacific coasts of America, which in time is sure to 

 affect very materially the geographic distribution of many of 

 the species of aquatic animals and plants in that region. It is 

 highly probable that in time many, if not all, of the brackish 

 water species of fishes and crustaceans and other invertebrates 

 of that region will find their way through the canal from one 

 side to the other; and it is not at all improbable that some 

 purely saltwater species will pass from one side to the other. 



But of still greater importance are the changes in the animal 

 and plant life which will result from the construction of the 

 Gatun Dam and the formation of Gatun Lake. This lake or 

 reservoir will cover many square miles of territory now entirely 

 out of water, and consisting of hills and valleys, and canyons and 

 small plains, through and among which run a number of large 

 rivers, such as the Rio Chagres, Rio Trinidad, Rio Gatun, and 

 a great number of smaller streams. Practically all of these 

 streams will be wiped out of existence when the land through 

 which they now flow becomes converted into the proposed large 

 lake. Some of the aquatic species inhabiting them will be wiped 



