REPORT ON MOSOTJITOES. 



103 



GAMBUSIA AFFINIS. 



Top-niiimozc. 



"A viviparous species, attaining a length of about one and 

 one-half to two inches. Its range is given as 'Delaware to 

 Mexico,' but it may possibly be found on the coast of New 

 Jersey. It is, at all events, easily obtained and transported. 



"This is a very active species, being constantly in motion, a 



Figure 29. 



Gambusia afUnis: the top-minnow: male above, female below. (From Jordan & Ever- 

 mann, Bull. 47, U. S. Nat. Mus.) 



top feeder, and penetrates to the shallowest edges of the waters 

 it inhabits. Being very small and slender, it easily glides over 

 masses of aquatic plants and penetrates among them as no other 

 fish does. It has been tested in small ponds and tubs during two 

 summers and no mosquito larv?e make their appearance when 



