486 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



I 



FAMILY LXXXV. PERCID^E. 



(The Fercliex.) 



Body more or less elongate, terete or compressed, covered more or less 

 completely with rather small, ctenoid, adherent scales. Lateral line 

 usually present, not extending on the caudal fin. Mouth terminal or 

 inferior, small or large, the premaxillaries protractile or not; maxillaries 

 large or small, without distinct supplemental bone. Jaws, vomer, and 

 palatines with bands of teeth, which are usually villiform, but sonic- 

 times mixed with canines; occasionally the teeth on the vomer or pala- 

 tines are absent. Head naked, or more or less scaly; preopercle entire 

 or serrate ; opercles usually ending in a flat spine. Branehiostegals 6 

 or 7. Gills 4, a slit behind the fourth ; gill-membranes free or connected, 

 not joined to the isthmus ; gill rakers slender, toothed ; pseudobranchiae 

 small, or glandular and concealed^ or altogether wanting ; lower pharyn- 

 geals separate, with sharp teeth. Fins generally large ; two dorsals, 

 the first of 6 to 15 spines; anal fin with one or two spines (three in 

 Fercichthys, a fresh- water genus from Chili). Veutrals thoracic, I, ."> ; 

 pectorals often very large; caudal lunate, truncate or rounded. Anal 

 papilla often present. Air bladder small and adherent, often entirely 

 wanting. Pyloric co3ca few. Vertebras, 30 to 45. 



Genera about 22 ; species, 90 to 100 ; inhabitants of the fresh waters 

 of cool regions, most of them being American and nearly all belonging 

 io the fauna of the United States. The great majority of the species 

 belong to the sub-family of EtheostomatincB, the Darters, all the species 

 of which group are American. They are among the most singular and 

 interesting of our fishes. They differ from the typical Farina' in their 

 small si/.e, bright colors, and large fins, and mere technically in the 

 rudimentary condition of the pseudobranehi;!' and the air bladder, both 

 of which organs are usually inappreciable. The preopercle is unarmed, 

 and the number of branehiostegals is six. An anal papilla is likewise 

 developed. ;is in the (iohiidtf, to which group the Darters bear a consid- 

 erable superficial resemblance, which, however, indicates no real al'linity. 

 The relations of the Darters to the Perches have been aptly expressed 

 by Professor S. A. Forbes: 



(liven a supply of certain kinds of food nearly inaccessible to the 

 oidinary fish, it is to be expected that some fishes would become 

 e>;u ci;ill\ fitted for its nt ili/at ion. Thus the l-'theostomatina- as a group 



