500 CONURIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY — IV. 
line; a black spot at the base of the caudal; fins barred. Head 4; 
depth 6. D. XV-15; A. II, 9; Lat. 1. 92. L. 6-8 inches. Great Lakes 
and streams of the South and West; the largest of the darters. 
(Scicena caprodes Rafinesqne, Amer. Month. Mag. 1818, 534: Pileoma semifasdalnm 
DeKay New York Fauna Fish. 1842, 16: Etheostoma caprodes, nebulosa, semifasciata, 
and Umaculata Storer, Synop. Fish. N. A. 270-272; Girard, Proc. Acad. Nat. Sci. Phila. 
1859, 66: Pileoma semifasciatum Gunther, i, 76: Pileoma caprodes Vaillant 1. c. 43; 
Jordan, Man. Vert. 220: Pileoma carhonaria Baird & Girard, Proc. Acad. Nat. Sci. 
I’hila. 1853, 387: Pileoma carhonaria Gunther, i, 76: Pileoma carhonaria Girard, 1859, 
10: Percina carhonaria Girard, Proc. Acad. Nat. Sci. Phila. 1859, 67; the latter a 
variety from Texas with the fins mostly higher.) 
Var. iiiaiiitoti Jordan. 
Space in front of spinous dorsal naked ; lateral bars short, more or 
less confluent, each one not meeting its fellow of the other side across 
the back; otherwise essentially as in the preceding, with which it inter- 
grades. Chiefly north westwanl ; abundant in Wisconsin. Examples 
intermediate between caprodes and manitou from Potomac Elver {Bean; 
Joiiy) and Illinois {Forbes). 
(^Percina manitou Jordan, Proc. Acad. Nat. Sci. Phila. 1877, 53.) 
261.— AL-VORDIUS Girard. 
BlacTc-sided Barters. 
{Etheostoma Agassiz; not of Rafinesqne.) 
(Girard, Proc. Acad. Nat. Sci. Phila. 1859, 68: type Alvoi-dius maculatus Girard.) 
Bodj^ rather elongate, little compressed. Mouth rather wide, ter- 
minal, the lower jaw included, the snout above not protruding beyond 
the premaxillaries, which are not protractile. Teeth on vomer, and 
usually on jialatiues also. Gill-membranes separate. Scales small, 
ctenoid, covering the body. Belly with a median series 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. 
Vertebrte 23 + 22 (A. aspro)-, 17 -f 22 {A. evides). Coloration bright; 
sides with dark blotches. The most active and graceful of the darters. 
(Dedicated to Maj. B. Alvord, who discovered “Jlvordins maculatus^’ at Fort Gratiot, 
on Lake Huron.) 
a. Vertebrae more than 40; dorsal spines 11 to 15; palatine teeth present. {Alvor- 
diu8.) 
h. Cheeks, opercles, and ante-dorsal region entirely scaleless; head very long and 
large; lat. 1. 75-80 macrocephalus. 
hh. Cheeks covered with fine scales; opercles with larger ones, 
c. Head very slender, with long acuminate muzzle; jaws nearly equal; space be- 
fore dorsal scaled; lat. 1. 65-70; lateral blotches small, quadrate. 
phoxocephalus. 
cc. Head stouter, with wider muzzle; lower jaw included aspro, nerisensis. 
