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. PERCINA MANITOU Jordan. 
Percina manitow, JORDAN, Proc. Acad. Nat. Sci. Phila., 1877, 53; Man. Vert. 2d Ed., 1878, 
220, and elsewhere. 
Description.—Body elongate, little compressed ; head slender, but less so than in P. 
caprodes, the snout being shorter, blunter, and less sloping; eye larger, 34 to 4 in head, 
with mouth rather small, little inferior, the maxillary not reaching quite 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 
snout to the preopercle; colors black and olivaceous, the back strongly marbled, the 
lateral bars short, not exteuding up the sides much above the lateral line; the bars 
are conflaent more or less, and about twenty in number, the last one blotch-like; a 
round, black caudal spot; dorsal and caudal fins mottled; head 44; 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 difference, I am unable 
to say. 
Genus 77. ALVORDIUS. Girard. 
_ Htheostoma, AGAssizZ, Amer. Journ. Sci. Arts, 1854, 354 (not of Rafinesque). 
Alvordius, GIRARD, Proc. Acad, Nat. Sci. Phila., 1859, 67. 
Ericosma, JORDAN, Bull. U.S. Nat. Mas., x, 1876, 8. 
Type, Alvordius maculatus, GIRARD. 
Etymology. Dedicated to Major B. Alvord. 
Body rather elongate, little compressed ; mouth rather wide, terminal, the lower jaw 
_- included, the snout above not protruding beyond the premaxillaries, which are not 
proiractile; teeth on vomer, and usually on palatines also; gill-membranes separate ; 
scales small, ctenoid, covering the body; belly with a median line of enlarged spinous 
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 
2; dorsal spines 10-15; vertebra 22 plus 22 ( 4. aspro), 17 plus 22 (A. 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. 
