FISHES OF PENNSYLVANIA. 137 

below it. The depth of the body is variable, equaling from one-sixth to one-fourth 
of the total without caudal; the head equals three-tenths of the same length. The 
skin is usually smooth or with minute prickles behind the axil of the pectoral. 
DPD. V{[-VIII, 16; A. 12-13; V. I, 4. 
The color is olivaceous, much speckied ; sides usually with several distinct, rather 
broad cross bands. 
Bull head, blob and muffle-jaws are names applied to the miller’s 
thumb, which has been associated with Richardson’s name. 
The typical Richardson’s miller’s thumb is found in the upper Great 
Lakes, but in Pennsylvania there are two varieties of it. The one known 
as Uranidea wilsoni, inhabits the Ohio valley, and the other, meridio- 
nalis, frequents the Alleghenies. The typical form ranges from Canada 
and the Great Lakes to Georgia and Arkansas. It is most abundant in 
stony brooks, cold lakes, caves and springs. Itis extremely variable in 
size, color and length of fins and number of rays. 
This species grows to a length of seven inches under favorable cir- 
cumstances and is one of the most destructive enemies of the eggs and 
young of brook trout and other members of the salmon family. 
155. Uranidea viscosa Hatpemay. 
The Slippery Miller’s Thumb. 
Body stout; well supplied with mucus pores. Depth of body much less than 
length of head, which is two-sevenths of the total without caudal ; the depth is scarcely 
more than one-fifth of this same length. A short sharp spine on the preopercle, 
turned obliquely upward. Fins low. 
TD): WAG Dev ses BIGAY Whe Lines 
The numerous mucus pores of the skin throw off a viscid secretion which has 
given rise to the specific name of this fish. 
Color olivaceous, mottled with darker. The spinous dorsal has a red edge. 
The slippery miller’s thumb is a species of apparently limited distri- 
bution. It was originally found in Pennsylvania by Prof. Haldeman and 
is known from only two other states, Maryland and Virginia. This isa 
small species, reaching a length of but three inches, and belongs to the 
section without palatine teeth. Nothing is recorded of its habits except 
that it is frequently found in caves. 
156. Uranidea gracilis Hecxet. 
The Slender Miller’s Thumb. 
The body is moderately slender, spindle-shaped ; mouth large, the upper jaw 
reaching nearly to the middle of the eye. The preopercular spine is moderately 
large, covered by skin. The pectorals reach to the origin of the anal, and the vent- 
rals to the vent. The depth of the body is one-fifth, and the length of the head two- 
sevenths of the total without caudal. Teeth in villiform bands on the jaws and 
yomer, none on the palatine bones. 
IDS WADE Gin OG ae 
The sides are olivaceous, mottled with darker. A red margin on spinous dorsal. 
The miller’s thumb or little star gazer is an inhabitant of New England 
and New York. In Pennsylvania it occurs in the headwaters of the 
