358 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
equal; mandible 2.85 in head; lateral line slightly decurved, nearly continuous, absent only on last 
scale; scales rather- small. Dorsal fin inserted behind front of ventral, its height 1.25 in head; anal 
1.53 in head; pectoral and ventral of moderate length, the former 1.53 and the latter 1.81 in head. 
Peritoneum pale. 
Coloration, above, dusky olive, somewhat speckled with brown; an irregular dusky stripe along 
the lateral line to base of caudal, ending in a small black spot; below lateral line creamy white with 
brownish spots on side; dorsal and pectoral dusky; other fins pale. Colors after preservation in 
formalin and later in alcohol very much intensified. 
Type, No. 50832, TJ. S. N. M., an individual 102 millimeters long, one of numerous specimens 
collected by W. C. Kendall and Thomas B. Gould in Bill Fish Brook, a tributary of the East Branch 
of the Penobscot River about a mile below Matagamon Lake, September 7, 1901. Cotypes, No. 2744, 
U. S. F. C. 
Named for lion. Leroy T. Carleton, chairman of commissioners of inland fish and game of Maine. 
It will be seen from the accompanying table that there is considerable individual variation among 
the specimens from this one locality. There is also found a locality variation which, though possibly 
accidental, seems from its constancy to be more than that. For instance, specimens from a small pond 
near Hale Pond, West Branch of the Penobscot River, show a slightly shorter head, the scales run a 
little smaller, and there are sometimes fewer anal fin rays, with some other minor differences. The 
male sometimes becomes brilliantly red along the side of the abdomen from behind the pectoral fin 
to the lower base of the caudal. This color persists to some extent on individuals until fall. 
Tig. 1 . — Leuciscus carlctoni Kendall, new species. 
Besides the type locality, this species has been taken in Smith Brook, which is the outlet of Hay- 
mock Lake, tributary to Eagle or Heron Lake of Allagash River and in thoroughfare between Long and 
Cross lakes, East Branch of the Fish River waters or Eagle Lakes of Aroostook County. It is doubtless 
widely distributed. 
The presence of a barbel possibly should inhibit placing it in the genus Leuciscus. In this respect 
it is allied to Sernotilus and Couesius. In Couesius the barbel is nearer the extremity of the maxillary 
than in this form, which in this respect is closer to Sernotilus, to which the pharyngeal teeth would 
take it, being most commonly 2, 4-5, 2, which seems not to occur in a large series of Couesius plurnbeus 
from Maine, or in other species. In fact, the generic distinction of Couesius seems to be the presence 
of only 4 teeth in each of the main rows. While teeth and barbel would suggest Semotilus, the incom- 
plete and sometimes broken lateral line forbids that disposition of it. The barbel, however, is absent 
from a few of the cotypes and seems not to be present on the Southards Pond specimens. 
Assuming that Leuciscus is the proper genus for it, which other minor characters would suggest, 
then it is closely allied to Leuciscus margarita Cope, under the subgenus Plioxinus. Leuciscus margarita, 
however, is proportionately a shorter and deeper fish, with slender caudal peduncle and larger scales. 
Our specimens have been compared with specimens of L. margarita from West Virginia and Lake 
Ontario, and barbels were found on some from the latter locality. Of 12 specimens, 4 had barbels on 
each side, 2 had a barbel on one side and none on the other, and 6 had no barbels at all. 1 Barbels on 
our specimens can not be accounted for by age, for they are present on large and small, and of those 
from which they were absent one is a large individual. Its general form, and especially of the head, 
is that of Couesius dissimilis, but in the latter the mouth is much larger than in Leuciscus carlctoni. 
