592 Chromides and Pharyngognathi 
analogy to the black bass of farther north. A vast number 
of species belonging to Heros, Acara, Cichlasoma, Geophagus, 
Chetobranchus, and related genera swarm in the Amazon region. 
Each of the large rivers of Mexico has one or more species; one 
of these, Heros cyanoguttatus, occurs in the Rio Grande and the 
rivers of southern Texas, its range corresponding with that of 
Tetragonopterus argentatius, just as the range of the whole family 
of Cichlide corresponds with that of the Characinide. No other 
species of either family enters the United States. <A similar 
species, Heros tetracanthus, abounds in the rivers of Cuba, and 
another, Heros beani, called the mojarra verde, in the streams 
of Sinaloa. In the lakes and swamps of Central America Cich- 
lide and Charactnide are very abundant. One fossil genus is 
known, called Priscacara by Cope. Prtscacara clivosa and 
other species occur in the Eocene of Green River and the Great 
Basin of Utah. In this genus vomerine teeth are said to be 
present, and there are three anal spines. None of the living 
Cichlid@ has vomerine teeth. 
The Damsel-fishes: Pomacentride.—The Pomacentride, called 
rock-pilots or damsel-fishes, are exclusively marine and have in 
all cases but two anal spines. The species are often very bril- 
liantly colored, lustrous metallic blue and orange or scarlet 
being the prevailing shades among the bright-colored species. 
Their habits in the reef pools correspond very closely with those 
of the Chetodontide. With the rock-pilots, as with the butterfly- 
fishes, the exceeding alertness and quickness of movement make 
up for lack of protective colors. With both groups the choice 
of rocky basins, crevices in the coral, and holes in coral reefs 
preserves them from attacks of enemies large enough to destroy 
them. In Samoa the interstices in masses of living coral are 
often filled with these gorgeous little fishes. The Pomacentride 
are chiefly confined to the coral reefs, few ranging to the north: 
ward of the Tropic of Cancer. Sometimes the young are colored 
differently from the adult, having sky-blue spots and often 
ocelli on the fins, which disappear with age. But one species 
Chromis chromts, is found in the Mediterranean. Chromis 
puncttpinnts, the blacksmith, is found in southern California, 
and Chromis notatus is the common dogoro of Japan. One of 
the largest species, reaching the length of a foot, is the Gari- 
