EIGENMANN— YELLOW FEVER AND FISHES. 207 



It can easily be caught, it can easily be transported, and will live at 

 any altitude in which the fever mosquitoes are likely to be found. 



With the chalacos available to control the mosquitoes along the 

 coast and the huaijas to control them from the coast to several thou- 

 sand feet, the means are at hand to entirely eradicate fevers from the 

 Pacific slopes of Tropical America. 



With the above paper, portions of a letter dated March 27, 1922, 

 were read, from Dr. Henry Hanson, Director General of the " Com- 

 pafia Sanitaria Contra la Fiebre Amarilla en el Peru." Dr. Hanson 

 reported that he was sending specimens of six species of fishes with 

 which experiments were made in mosquito control. He says in part : 



We found two to be very good larvse destroyers. ... I think our campaign 

 has demonstrated that using fish is the only rapid method of handling a yel- 

 low fever epidemic. 



Dr. Hanson further reports that only two of the six species tried 

 proved valuable. They are the fishes known locally as " chalquoque " 

 and "life," pronounced le-fa. 



Addenda. 



The " chalquoque " is Lehiasina bimaculata C. & V., called " liza 

 de agua dulce " in Lima, and is the " huaijas " so successfully used for 

 mosquito work in Guayaquil. It is found everywhere between Lima 

 and Guayaquil, and in the Rio Rimac it is found from sea level to 

 Matucana at over 7,000 feet. 



Another member of the genus is found in the Atrato and San 

 Juan basins in Colombia. Species of a very closely related genus, 

 Piabiicina, are found from Guayaquil north to the Chagres. The 

 species will be considered, several of them figured in a volume on the 

 fishes of northwestern South America now going through the press 

 (Mem. Carnegie Miis., IX., 1922). The species are members of the 

 Lebiasinince of the Characidse. 



The " life " is Pygidium punctnlatum piurce E., recently de- 

 scribed by myself from Piura. It is much of a surprise that this 

 species proves to be a mosquito larva eater. It is, as far as known, 

 restricted to northwestern Peru, but a close relative, P. punctidatum 

 (C. & V.) is found in the Rio Rimac from the ocean to several 

 thousand feet at least. It is the "bagre" of the Rio Rimac. The 



