FISHES OF NEW YORK 531 



hering eggs was introduced into a wide aquarium fungus also 

 attacked the eggs as before but the results were somewhat 

 more favorable. With the water at 58° to 60° F. the eggs 

 hatched out in 6 days. 



The white perch congregates in large schools and is one of 

 the freest biters among fishes. The shrimp is one of the best 

 baits, though worms, sturgeon eggs, minnows and strips of cut 

 fish with silvery skin are equally effective. Dr Abbott has 

 known as many as 20 dozen to be taken with a line in a few 

 hours, and Spangler mentions catches of six or seven hundred 

 in a day by two rods, the fish ranging in weight from f to 1^ 

 pounds. 



Eugene Smith, on several occasions, found a long, green, 

 brackish-water alga (Enter omorpha) in stomachs <>f 

 white perch, indicating that they sometimes eat vegetable mat- 

 ter, though perhaps only for the minute organisms found 

 upon it. 



In captivity the fish is very susceptible to fungus attacks, but 

 the parasite is readily killed by changing the water supply 

 from salt to fresh, or vice versa. 



Genus polyprion Cuvier 

 Body robust, moderately elevated, not much compressed, cov- 

 ered with small, firm, ctenoid scales which extend on the bases 

 of the vertical fins. Lateral line complete, partly concealed 

 under adjacent scales, the tubes covering the whole length of 

 the scale. Mouth large, the lower jaw projecting; maxillary 

 with supplemental bone. Teeth in broad, villiform bands on 

 jaw^s, vomer, palatines, and tongue; no canine teeth. Head 

 scaly. Preopercle serrate; orbital region with spinous projec- 

 tions; opercle with a strong spine and with a strong, rough, 

 bony longitudinal ridge; gill membranes separate; gill rakers 

 long, few. Dorsal fin continuous, low, with 11 strong spines 

 and 11 or 12 rays, the spinous portion longest; caudal rounded; 

 anal short, with three spines, the third the longest; ventrals 

 large, inserted below, little behind pectoral; caudal rounded or 

 truncate; pectorals short, unsymmetrical, of 18 or 19 rays, the 



