AQUARIUM FISHES 341 



larger than the male and plain olive in color. This fish is 

 very abundant at certain points, inhabiting ponds, brooks 

 and even ditches. It is found associated with males which 

 lack the black spots, and are known as G. aifinis. It seems 

 probable that the two types represent mere color phases of 

 one species, as the females are not separable, but little is 

 known concerning this point. Wild-caught fishes do not 

 always breed true to color, the young often reverting to the 

 affinis phase, but strains of aquarium-bred fishes have been 

 formed the progeny of which come true to type. This 

 is a very prolific but exceedingly voracious fish, necessitating 

 the seclusion of the mothers if any of the young are to be 

 reared. It is hardy, does not require so high a temperature 

 as many others, and will thrive on the usual foods, but be- 

 cause of its pugnacity cannot be associated with other 

 species. 



Several forms of Platypoecilius are popular among ad- 

 mirers of aquarium fishes. The best known is P. maculatus, 

 a rather plainly colored olive fish, usually diversified by 

 dark caudal spots and bluish sides. It rarely much exceeds 

 an inch and one-half in length, but is very deep in com- 

 parison. There are various other handsomely colored forms, 

 varying in color between the extremes of bright red and 

 velvety black. Some have been named, but as they inter- 

 breed freely their specific standing is very much in doubt. 

 All are quiet, harmless fishes, of vegetarian habit and easily 

 kept. 



Pcecilia is a very widespread genus, extending from 

 Mexico to northern South America and the West Indies. 

 There are many species, only a few of which have been kept 

 in America. P. sphenops, P. pavonina, P. amazonica and 

 P. vivipara are the best known. All are handsome, sociable 

 fishes, subsisting chiefly on a vegetarian diet, and may safely 

 be kept with other fishes. 



