YELLOW BASS. 967 



among the most singnlar and inteiesting of onr fishes. They diffei from the typical 

 PercincB in their small size, bright colors, and large fins, and more technically in the 

 rndimentary condition of the psendobranchise and the air-bladder, both of which organs 

 are usually inappreciable. The preopercle is nnarmed, and the number of branchiostegals 

 is six. An anal papilla is likewise developed, as in the Goiiidoe, to which group the 

 Darters bear a considerable superficial resemblance, a resemblance, however, which in- 

 dicates no real affinity. 



The colors of the Etheoitomatince are usually very brilliant, species of PoBcilichthys, 

 NortJwnotus, and Dipletium being among the most brilliantly colored fishes known ; the 

 sexual difiEerences are often great, the females being as a rule dull in color and more 

 speckled or barred than the males. Most of them prefer clear running water, where 

 they lie on the bottom concealed under stones, darting, when frightened or hungry, with 

 great velocity for a short distance by a powerfal movement of the fan-shaped pectorals, 

 then stopping as suddenly. They rarely use the caudal fin in swimming, and they are 

 seldom seen moving or floating freely in the water like most fishes. When at rest, they 

 support themselves on their extended ventrals and anal fin. All of them can turn the 

 head from side to side, and they frequently lie with the head in a curved position or 

 partly on one side of the body. 



Ammoerypta, and perhaps some of the others, prefer a sandy bottom, where, by a sud" 

 den plunge, the fish buries itself in the sand and remains quiescent for hours at a time, 

 with only its eyes and snout visible. The others lurk in stony places, under rocks and 

 weeds. Although more than usually tenacious of vitality from their bottom life, the 

 Darters are the first to be disturbed by impurities in the water. All the Darters are 

 carnivorous, feeding chiefiy on the larvae of gnats, and, in their way, voracious. All are 

 of small size ; the largest, Pnrcina, reaches a length of eight inches, while the smallest, 

 Microperca, is probably the smallest spiny- rayed fish known, barely attaining the length 

 of an inch and a half. They are of too small size to be used for food, although, accord- 

 ing to Eafineeque, " they are good to eat, fried." 



The Percince are represented in America by two genera, and in Europe by the same 

 two and three others— ^cerina, Percarina, and Aapro —the latter bearing a strong external 

 resemblance to the MheoatomaUnoe, and serving as a connecting link between them and 

 the more typical forms. 



Analysis of Gbnbra of Pbkcid^. 



a. Pseudobranchia) well developed ; preopercle serrate ; branchiostegals 7. 



{PereincB.) 



6. Canine teeth none ; body oblong Pbrca.. 



ib. Canine teeth in jaws and palatines ; body elongate. . . . Stizostedium. 

 aa, Psendobranchise imperfect or wanting ; preopercle entire; branchiostegals 6. 



{Eiheostotnatince. ) 

 0. Premaxillaries protractile. 



d. Body extremely elongate, suboylindiical, translucent, the belly at least 

 naked ; lateral line complete ; gill-membranes broadly united. 

 e. Anal spine single ; anal fin nearly as large as second dorsal. 



Ammocbtpta. 

 dd. Body less elongate, opaque, chiefly scaled. 



/. Anal spine obscure, normally single ; lateral line complete. 



BOLEOSOMA,. 



ee. Anal spines two, the first commonly the longer. 



