OU PEBCID-f:. 



B. Jaws with a lateral series of laryer teeth, or ivith canines. 



1. With canmca. Snout very short, rounded ; fins partly elon- 



gated ; dorsal with eleven sjjines ; operculum spiniferoua ; 



pnuoperculuin entire 22. C'allantihas. 



2. With a lateral aeries of larger teeth. 



a. Oj)i'rcu/u7n spinifcrous : apinesof the fins slender. Fonn 

 of body cylindrieal ; dorsal deeply notehed, the firat 

 portion with nine spines ; prjEopercolum serrated ; 

 scales small '. 3. PARALAnitiVx. 



h.- Opcradum not armed ; spines of the fins very strong. 

 Form of body rather elevated ; dorsal deeply notched, 

 the first portion with ten spines ; scales rather small. 58. Anoplus. 



c. Opercultim indisfincfli/ armed ; fmsal half of the dorsal 

 fin scaly. Form of the body compressed, oblong; 

 one dorsal, with ten si)incs; scales moderate, not 

 eerrated ; caudal deeply forked 51). Odontc.nectes. 



IV. Number of the brancJiiostegals varyimj between Jive and s^ix. 



No canine or palatine teeth. Two dorsals, united at the base 

 only ; the first with nine spines, the anal witli tiiree ; no 

 distinct armatiu-e on the opercles ; scales moderate 54. I'eiccilia. 



These genera may be combined into more natural groups. In 

 these* groups one or other of the manifold characters predominates, 

 without being appli(;uble to every member of the grou]). If we follow 

 Cmier and make the categories strictly depend upon one character, 

 then we arc obliged to separate Perca and I'erdchthijsi. merely because 

 the former has seven, the latter sometimes six branchiostcgals — or 

 Grammistes and lihyptlcus, merely because in the former the spinous 

 part of the dorsal is more developed, and separated from the soft one 

 by a deep notch— or Apogon and Chilodiptcms, because in one there 

 are conspicuous canines ; and yet there are no fishes more closely 

 allied than those of the thi-ee pairs mentioned. When we become 

 acquainted hereafter with more generic forms, then the Perddcp. will 

 be chvidcd into many groups or families \\-ith more exact characters ; 

 and the following natural combination is merely an attempt at a 

 systematic division of these fishes. 



I. Group with the type of Perca. — Mostly tresnwater fishes, or 

 sea fishes entering the rivers. Form of the body oblong, rarely 

 cylindrieal or elevated. Opercles strongly denticidated or armed. 

 Scales conspicuously ctenoid, snuill, or of moderate size. Cleft of 

 mouth horizontal or slightly oblique. Mostly with two dorsals; the 

 number of spines constant in the species of one genus. Rarely more 

 than ten pyloric appendages. Percina. 



