422 
BULLETIN OF THE UNITED STATES PISH COMMISSION. 
Genus XXXI.— EOCCUS. 
Roccus Mitchill, Fishes of New York, 25, 1814 {siriatus—lineatus). 
Lepibema Ratinesque, lohthyologia Ohiensis, 23, 1820 {chrysopa). 
Roccus Gill, Pi'oc. Ac. Nat. Sc;. Phila., 18C0, 111. 
Lepibema Steiudachner, substitute for Morone aucl Roccus. 
Type. — Boccus striatus Mitchill Hneata Bloch. 
Etymology . — From the vernacular, Eock-fish. 
This group contains two species, about equally allied to Morone and to Dicen- 
trarchus. 
ANALYSIS OF SPECIES OF ROCCUS. 
Common characters: As in Afoj-oac except as follows: 
Base of tongue with one or two patches of teeth ; anal spines graduated ; dorsal fins entirely separate ; 
anal rays, HI, 11 or 12; supraoccipital crest scarcely widened above; lower jaw projecting; 
spines rather slender. 
a. Teeth on base of tongue in a single series; body rather deep and compressed, the depth more 
than one-third the length; back considerably arched {Lepibema Rafinesque); head subconical, 
slightly depressed at the nape; mouth moderate, nearly horizontal, the lower jaw little 
projecting; eye large, as long as snout, about 5 in head ; maxillary reaching middle of pupil, 
2f in head ; margin of subopercle with a deep notch ; gill-rakers rather long and slender, x + 12; 
longest dorsal spine 2 in head ; second anal spine 3 ; color silvery, tinged with golden below ; 
sides with narrow, dusky lines, about five above the lateral line, one along it, and a variable 
number below it, these sometimes more or less interrupted or tramsposed. Head, 3^ in length; 
depth, 2^. D. IX — I, 14; A. Ill, 12 Chrysops, 116. 
aa. Teeth on base of tongue in two parallel patches; body rather elongate, little compressed, the 
depth less than one third the length ; back little arched {Roccus Mitchill); head subconical; 
mouth large, oblique, the maxillary reaching to below middle of orbit, 2^ in head; eye about 
half the length of the rather sharp snout, 7 in head ; margin of subopercle entire ; suprascap- 
ula entire; maxillary naked ; gill-rakers long and slender, 4 -f- 12 ; spines slenderer than in any 
other species; longest dorsal spine in head; second anal spine 5; color olivaceous, silvery, 
often brassy-tinged; sides paler, marked with seven or eight continuous blackish stripes, one 
of them along the lateral line. Head, 3| in length ; depth, 3J, varying considerably with age, 
the young being more slender. D. IX-I, 12; A. Ill, 11; Scales, 8-67-11 Lineatus, 117. 
116. ROCCUS CHRYSOPS. 
(The White Bass. White Lake-Bass. 
Perea chrysops Rafinesque, Ichthyologia Ohiensis, 22, 1820 (Falls of the Ohio). 
Labrax chrysops Gill, Proc. Ac. Nat. Sci. Phila., 1860, 20. 
Roccus chrysops Gill, Proc. Ac. Nat. Sci. Phila.. 1860, 113 (Racine ; Toronto ; southern Illinois) {not Lahrax 
chrysops Girard; not Labrax multilineatus Giinther, I, 501): Gill, Ichth. Rep. Captain Simp- 
sou’s Sur. Great Basin Utah, 391, 1876; Cope, Proc. Ac. Sci. Phila., 1865, 83 (Saginaw Bay); 
Milner, Rep. U. S. Fish Com., 1872-73, 76; Jordan, Man. Vert., 1876, 226; Nelson, Bull. Ills. 
Mus. Nat. Hist., 1876, 36; Jordan & Copeland, Bull. Buffalo Soc. Nat. Hist., 1876, 136; Jordan, 
Fishes Illinois, 44, 1877 (Lake Michigan ; Quincy; Henry); Jordan & Gilbert, Klippart’s Rept. 
Fish Commissioner Ohio, 1878; Jordan, Man. Vert., Ed. II, 1878; Jordan, Geol. Sur. Ohio, 
955, 1882; Jordan, Annals N. Y. Ac. Sci., IV, No. 4, 97, 1876 (Lakes Winnebago, Erie, and Mich- 
igan; Fox and Miss. Rivers); Jordan & Brayton, Bull. U. S. Nat. Mus., 1873, 83 (Ohio and 
Illinois Rivers.); Jordan, Nat. Hist. Aquat. Anim., 428, 1884; Jordan & Gilbert, Proc. U. S. 
Nat. Mus., 1886, 12 (Washita and Saline Rivers, Arkansas). 
Labrax multilineatus Cuv. & Val., Hist. Nat. des Poissons, III, 488, 1830 (Wabash River); Kirtland, 
Boston Journ., Nat. Hist., V, 21, pi. 7, f 1, 1845; Storer, Syu. Fishes N. Am. 22, 1846 ; Giinther, 
I, 67, 1859 (Lake Erie ; Ohio River). 
