that spread Disease. 21 



Giles, and var. minutus Theob., A. (Myzomyia) rossi Giles, A. 

 (M.) funfstus Giles, A. (Pyretophorus) costalis Loew, A. (C cilia) 

 argyrotarsis Eob.-Desv., Culcx fatigans Wied., Stegomyia pseu- 

 doscutellaris Theob., Mansonioidcs uniformis Tbeob., Tacnio- 

 rhynchus titillans Walk., T. pscudotitillans Theob. 



FISHES THAT FEED UPON THE LARVAE 

 OF MOSQUITOES. 



By reducing the numbers of the larvae, and consequently the 

 number of mosquitoes, certain fishes are beneficial in their effect, 

 and lessen the chance of transmission to man of mosquito-borne 

 diseases. 



The five fishes exhibited in the glass vessel of alcohol are 

 denoted by letters. A is the male, and B the female of a little fish 

 known as " millions " (Lebistes reticulatus Peters). C is a female 

 specimen of a " top-minnow " (Gambusia affinis Girard). D is a 

 male, and E a female of Haplochilus pumilus Blgr., a fish without 

 a popular name. 



" Millions " (A and B) occur in fresh and brackish waters of 

 Venezuela, Guiana, Trinidad, and the Windward Islands. The 

 correct scientific name is Lebistes reticulatus, but the species has 

 also been described as Girardinus poeciloides (from Barbados), as 

 Gimrdinus guppyi (from Trinidad), and as Poecilia reticulata 

 (from Venezuela). The females are viviparous ; the males are 

 smaller than the females, and have ornamental markings, whereas 

 the females are plain in coloration. " Millions " are very prolific, 

 producing a brood every few weeks. They have been exported 

 into various tropical countries for the purpose of reducing the 

 numbers of mosquitoes, but those recently introduced into Africa 

 are said to have been devoured by the frogs. 



" Top-minnows " (C) like " Millions," are viviparous, and 

 belong to the Poeciliine group of the Cyprinodont fishes ; they 

 inhabit the Mississippi and fresh and brackish waters from Florida 

 to Texas. 



Ifiiplochiliis pumilm occurs in Lake Tanganyika and Lake 

 Victoria in Central Africa ; it is oviparous, and although it is known 

 to devour mosquito-larvae but little has been recorded as to its 

 natural history. 



