The Scyphophori, Haplomi, and Xenomi 199 



belong to Fundulus, a genus widely distributed from Maine 

 to Guatemala and north to Kansas and southern California. 

 Fundulus majalis, the Mayfish of the Atlantic Coast, is the 

 largest of the genus. Fundulus heteroclitus, the killifish, the 

 most abundant. Fundulus diaphanus inhabits sea and lake 



FIG. 158. Death Valley Fish, Empetrichthys merriami Gilbert. Amargosa Desert, 

 Cal. Family Poeciliidce. (After Gilbert.) 



indiscriminately. Fundulus stellifer of the Alabama is beauti- 

 fully colored, as is Fundulus zebrinus of the Rio Grande. The 

 genus Zygonectes includes dwarf species similar to Fundulus, 

 and Adinia includes those with short, deep body. Goodea 

 atripinnis with tricuspid teeth lives in warm springs in Mexico, 



Fie. 159. Sword-tail Minnow, male, Xiphophorus helleri Heckel. The anal fin 

 modified as an intromittent organ. Vera Cruz. 



and several species of Goodea, Gambusia, Pcecilia, and other 

 genera inhabit hot springs of Mexico, Central America, and 

 Africa. The genus Gambusia, the top-minnows, includes nu- 

 merous species with dwarf males having the anal modified. 

 Gambusia affinis abounds in all kinds of sluggish water in 



