MILLER’S THUMB 989 
cent” under stones in clear gravelly brooks, after the manner of the Darters. This 
species has not yet been noticed in Ohio, but it may probably be found in tributaries 
of Lake Erie, in the north-easterao part of the State. 
161. URANIDEA RICHARD3ONI (Agassiz) Jordan and Gilbert. 
= Miller’s Thumb; Biob; Mufle-jaws; Cave Bull-head. 
a. var. richardsoni. (Upper Lakes.) 
Cottus richardsoni, AGASSIZ, Lake Superior, 1850, 300 ; GrRARD, Mon. Cott., 1850, 39.—Gun- 
THER, li, 1850, 158. 
b. var. bairdi. (Ohio to N. Y.) 
Cottus bairdi, GIRARD, Proc. Am. Ass. Adv. Sci., 1850, 410; and Mon. Cott, 44. 
c. var. wilsoni. (Ohio Valley. ) 
Coitus wilsonit, GIRARD, Mon. Cott., 1851, 42. 
d. var. alvordi. (Wisconsin and Michigan.) 
Cottus alvordi, GIRARD, Mon. Cott., 1851, 46. 
é. var. meridionalis. (Alleghanies. ) 
Cottus meridionalis, GIRARD, Proc. Ass. Adv. Sci., 1850, 410; and Mon. Cott., 1851, 47. 
f. var. zopherus. (Alabama basin. ) 
Potamocottus zopherus, JORDAN, Ann. Lye. Nat. Hist. N. Y., 1876. 
g. var. caroline. (Ohio Valley and southward.) 
Potamocottus caroline, GILL, Proc. Bost. Soc. Nat. Hist., 1861, 40. 
Description.—Olivaceous, more or less barred and speckled with darker; fins mostly 
barred or mottled ; body slender or stout, tapering regularly backward to the tail; ver- 
tex somewhat depressed; interocular space with a groove; preopercle with a short, 
sharp spine, little hooked, directed backwards and upwards, mostly covered by the 
skin; below this are 2 smaller concealed spines; subopercle with a stoutish spine, 
directed forwards; skin smooth, except the region immediately behind the pectorals, 
which is beset with very small sharp prickles; these are sometimes obsolete; lateral 
line conspicuous, continuous or interrupted behind ; first dorsal low and feeble; pectoral 
fins large, their length nearly equal to that of the head, their tips usually reaching be- 
yond the origin of the soft dorsal; ventral fins moderate; isthmus very broad, the gill- _ 
membranes not forming a fold across it; head 34; depth 4-6; D. VI to VIII, 16 or 17; 
A. about 12; V.1, 4. Length 3 to 6 inches 
Habitat, Middle and Northern States, and probably northward; abounding in all clear 
rocky brooks and lakes southward along the Alleghanies. 
Notre.—As understood by us, Uranidea richardsoni is a wide spread and abundant species, 
varying in different regions, as is the case with most non-migratory species. In this as 
