Chromides and Pharyngoguathi 3s 
analogy to the black bass of farther north, \ vast number 
of species belonging to Aeros, deara, Crehdasoma, Geoplagus, 
Chetobranchas, and related genera swarm in the Amazon region, 
Rach of the large rivers of Mexico has one or more species; one 
af these, dderos chamoguilades, oceurs in the Rio Grande and the 
rivers of southern TPoxas, its range corresponding with that of 
Petragonopteris argentatias, Just as the range of the whole fanily 
at CYehtidke corresponds with that of the Charactnide No other 
species af etther family enters the United States. A) similar 
species, Heros fetracantius, abounds in the rivers of Cuba, and 
smother, Eferos deand, eatled: the mojarra verde, in the streams 
af Sinaloa, In the lakes and swamps of Central America (Céch- 
lide and Charactide ave very abundant. One fossil genus is 
known, called Precacana by Cope. Préscacara elftesa and 
other species occur in the Boeene of Green River and the Great 
Basin af Utah. In this genus vamerine teeth are said to be 
present, and there ate three anal spines, None of the living 
Crehlide have vamerine teeth, 
The Damsel-fishes: Pomacentrida. The Pomacentride, called 
rock-pilots or damsel-fishes, are exclusively marine and have in 
all cases but Owe anal spines. The species are atten very bril- 
Viantly 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 
at the Chetodontide. With the rock- pilots, as with the buttertly- 
tishes, the exceeding alertness and quickness of movement make 
up for lack af protective colors, With both groups the choice 
at rocky basing, crevices in the coral, and holes in coral: reets 
preserves them fram attacks af enenttes hinge enough to destroy 
them. In Samoa the interstices in masses of living coral are 
atten tiled with these gorgeous little fishes, The Powscenérie 
are chiefly confined to the coral reefs, few ranging fo the north- 
want af the Tropic of Cancer, Sometimes the vourng ate colored 
differently fram the adult, having sky-blue spots and often 
ecelli on the tings which disappear with age But one spectes 
Chromis chrom’s, is) found ine the Modtterranean. Or onees 
punctioderd’s, Une blacksmith, ts found: in southern California, 
and Chromeds notatas is Che common dogore of Tappan, One of 
the largest species, reaching the length of a foot is the Gane 
