LOG-PERCH. 971 



be sometimes taken with a small hook, and is often brought home 

 by boys. Its flesh is excellent, but it is too small to have any import- 

 ance as a food fish. 



139. Pbrcina manitou Jordan. 



Perdna manitou, Jordan, Proc. Acad. Nat. Soi. Phila., 1877, 53 ; Man. Vert. Sd Ed., 1878, 

 220, and elsewhere. 



Deacription. — Body elongate, little compressed ; head slender, bat less so than in P. 

 oaprodes, the snont being shorter, blunter, and less sloping ; eye larger, 3J to 4 in head, 

 with month rather small, little inferior, the maxillary not reaching qnite to the eye ; 

 cheeks and opercles with small scales ; chest naked ; space in front of spinous dorsal 

 naked ; fins moderate, the height of the soft dorsal less than the distance from the 

 snont to the preoperole ; colors black and olivaceous, the back strongly marbled, the 

 lateral bars short, not extending np the sides much above the lateral line ; the bars 

 are confluent more or less, and abont twenty in number, the last one blotch-like ; a 

 round, black caudal spot ; dorsal and caudal fins mottled ; head 4J ; depth 7 ; D. XV, 

 14 ; A. II, 10 ; Lat. 1. 90. Length 5 inches. 



Habitat, Lakes of Northern Indiana, Michigan, and Wisconsin ; specimens variously 

 intermediate between this and the preceding found in the Potomac River (Bean), and, 

 in Illinois (Forbes). This form is usually well marked in color and in other respects ; but 

 it is doubtful whether it can be maintained as a distinct species. 



Habits. — This form has been thus far chiefly taken in lakes ; the other, 

 (caprodes) in rivers. Whether this is a constant difierence, I am unable 

 to say. 



Qbnds 77. ALVOEDIUS. Girard. 



Etheosioma, Agassiz, Amer. Journ. Sci. Arts, 1854, 354 (not of Kafinesque). 

 Alvordim, Girard, Proo. Acad, Nat, Sci. Phila., 1859,'67. 

 Uricosma, Jordan, Bull. U. S. Nat. Mns., x, 1876, 8. 



Type, Alvordius maeulatus, Girard. 

 Etymology. Dedicated to Major B. Alvord. 



Body rather elongate, little compressed ; month rather wide, terminal, the lower jaw 

 included, the snout above not protruding beyond the premaxiUaries, which are not 

 protractile ; teeth on vomer, and usually on palatines also ; gill-membranes separate ; 

 scales small, ctenoid, covering the body ; belly with a median line of enlarged spinons 

 plates, which fall off, leaving a naked strip ; sides of head scaly or not ; lateral line 

 complete ; fins large, the soft dorsal smaller than the spinous or the anal ; anal spines 

 3; dorsal spines 10-15 ; vertebrae 22 plus 22 (A., aspro), 17 pins 22 (4. evides) ; coloration 

 bright; sides with dark blotches. 



Darters of moderate size, having greater powers of swimming freely" 

 in the water than any of the other genera. The species are among the 

 most graceful in form and elegant in coloration of all American 

 fishes. This species is very close to Percina, from which it differs only 

 in the form of the mouth. 



