Percoidea, or Perch-like Fishes 519 
The black bass is now introduced into the streams of Europe 
and California. There is little danger that it will work injury 
to the trout, for the black bass prefers limestone streams, and 
the trout rarely does well in waters which do not flow over 
granite rock or else glacial gravel. 
The large-mouth black bass (Mucropterus salmoides) is very 
much like the other in appearance. The mouth is larger, in 
the adult cleft beyond the eye; the scales are larger, and in 
the young there is always a broad black stripe along the sides 
and no cross-bands. The two are found in the same region, but 
almost never in the same waters, for the large-mouth bass is a 
fish of the lakes, ponds, and bayous, always avoiding the swift 
currents. The young like to hide among weeds or beneath 
lily-pads. From its preference for sluggish waters, its range 
extends farther to the southward, as far as the Mexican State 
of Tamaulipas. 
Plhioplarchus is a genus of fossil sunfishes from the Eocene 
of South Dakota and Oregon. Plioplarchus sexspinosus, sep- 
temspinosus, and whitet are imperfectly known species. 
The Saleles: Kuhliidz.—Much like the sunfishes in anatomy, 
though more like the white perch in appearance and habit, 
are the members of the little family of Kuhliude. These are 
active silvery perches of the tropical seas, ponds, and river- 
mouths, especially abundant in Polynesia. Kuhlia malo is 
the aholehole of the Hawaiians, a silvery fish living in great 
numbers in brackish waters. Auslia rupestris, the salele of the 
Samoan rivers, is a large swift fish of the rock pools, in form, color, 
and habits remarkably like the black bass. It is silvery bronze 
in hue, everywhere mottled with olive-green. The sesele, Kuslia 
marginata, lives with it in the rivers, but is less abundant. The 
saboti, Kuhlia teniura, a large silvery fish with cross-bands on 
the caudal fin, lives about lava-rocks in Polynesia from the 
Galapagos to Samoa and the East Indies, never entering rivers. 
Still other species are found in the rock pools and streams of 
Japan and southward. 
The skeleton in Kuhlia is essentially like that of the black 
bass, and Dr. Boulenger places the genus with the Centrarchide. 
The True Perches: Percide.—The great family of Percide 
includes fresh-water fishes of the northern hemisphere, elon- 
