2708 THE BONY FISHES AND GANOIDS 



eighteen inches in length, the common species may grow to three feet; but its flesh 

 is then much less delicate than that of ordinary specimens. Bass frequent the coast 

 in shoals, spawning in summer generally near the mouths of rivers, up which they 

 not unfrequently ascend for considerable distances. 



In the other genera of the subfamily the dorsal fin is undivided, al- 

 though it may be deeply notched; the number of its spines being gener- 

 ally nine or eleven, although there may be either eight, ten, or twelve. Under the 

 common title of sea perches may be included the members of several allied genera, 

 such as Centropristes and Anthias, although the name is often restricted to those of 

 the typical genus Serranus, one of which (S. scriba) is represented in the middle 

 figure of the preceding illustration. In the sea perches the body is oblong or com- 

 pressed, and covered with small ctenoid or cycloid scales; there are large tusks 

 among the villiform teeth of the jaws; and teeth are also present on the palatines 

 and vomers, although absent from the tongue. The preopercular bone is serrated 

 behind and at the angle, but not inferiorly; and the tail fin may be either rounded, 

 squared, or emargiuate. The sea perches of the genus Serranus, of which there are 

 an enormous number of species, range through the seas of all the tropical and tem- 

 perate regions, occasionally ascending tidal rivers for short distances in pursuit of 

 prey, but being otherwise strictly marine. Many of the species vary considerably, 

 both in color and in the form of their fins, with age, so that specific distinctions are 

 difficult to establish. Extinct species of this genus, as well as others belonging to 

 Lates, occur in the middle Eocene deposits of Italy. 



The fish represented in the lower figure of the preceding illustration, 

 and commonly known as the stone bass {Polyprion cernuum), is 

 one of two species constituting a genus distinguished from the last by the absence 

 of large tusks in the jaws, and the presence of teeth on the tongue; the single dor- 

 sal fin having eleven or twelve spines, and the anal three. The preopercular bone 

 is denticulated, and there is a strongly-marked rough longitudinal ridge on the 

 opercular. The common species is abundant on the European coasts, while the 

 second is from the seas of Juan Fernandez. Both attain a very large size, ranging 

 in weight to eighty pounds or more, their flesh being of excellent quality. The Eu- 

 ropean stone bass frequents the neighborhood of floating wood, probably for the pur- 

 pose of feeding on the creatures to be met with around such objects. 



The two species of the genus Lates, one of which (L. niloticus*) in- 

 Oriental and habits the mollt h O f t h e Nile, while the second (L. calcarifer) ranges 



Atrican 



Perches from tne shores of Baluchistan through the Indo- Malayan seas to 



China and Australia, may be taken as representatives of another sub- 

 family (Centropomina} , with three genera; this subfamily differing from the last by 

 the extension of the lateral line on to the tail fin, the presence of a scaly process 

 at the bases of the pelvic fins, and the small size or absence of the false gills. Hav- 

 ing no teeth on the tongue, and a divided dorsal fin, these fish may be distinguished 

 externally from the true perches by the presence of seven or eight dorsal and three 

 anal spines. Both the preopercular and the preorbital bones are serrated, and the 

 latter denticulated at the angle; the finely pectinated scales being of moderate size. 

 The Indian perch, which may grow to a length of five feet, is the only Oriental 



