146 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
of Eagle Lake, is not found elsewhere. Honey Lake and Truckee River basins have 
5 native species in common — Pantosteus lahonton , Catostomus talioensis, Rutilus 
olivaceus, Agosiarobusta, and Coitus beldingii. Salmo irideus is found in both basins, 
but it has been introduced into Truckee Basin, and possibly into Honey Lake Basin. 
Leuciscus egregius is also known from Honey Lake Basin, and Coregonus williamsoni 
and Salmo lienshawi from Truckee Basin. Salvelinus fontinalis has been intro- 
duced into the latter basin. 
Pantosteus lahonton Rutter, new species. 
Head 4.5 in length, depth 5.5; eye G in head; D. 10 or 11; A. 7; scales 17-81 to 96-12, 47 to 50 
before dorsal. Body terete, caudal peduncle hut little compressed; interorbital slightly convex, or 
flat, width of bone 2.8 in head; eye posterior, 3 in snout, 2.5 in interorbital space, 1.5 in distance 
between eye and upper end of gill-opening; snont equal to half of head, broadly rounded both ver- 
tically and horizontally, projecting beyond the large mouth; 4 rows of papillae on upper lip, 4 
rows across symphysis of lower lip, 10 papillae in an oblique row from corner of mouth to inner corner 
of lobe of lower lip; isthmus broader than interorbital, equal to distance between pupils; fontanelle 
present, but less than half width of pupil in a 6 -inch specimen; dorsal inserted from 49 to 52 
hundredths of body from tip of snout; ventrals inserted under ninth ray of dorsal, halfway 
between tip of snont and tip of middle caudal rays; caudal 1.5 in head, deeply emarginate, not 
forked; pectoral 1.3 in head; height of dorsal about 1.4 in head, the base equal to snout, margin 
slightly emarginate; ventrals 1.7 to 1.8 in head. Very dark, almost black above, abruptly paler 
below, lower fins slightly dusky. Maximum length, about 6 inches. 
Closely related to Pantosteus generosus, but with the following differences, determined by 
comparison with specimens of that species of the same size from Provo, Utah. The Provo speci- 
mens have the dorsal 10 or 11 instead of 9 or 10, as described by Jordan & Evermann. 
Species. 
Interor- 
bital 
space. 
Scales in 
lateral 
line. 
Scales 
before 
dorsal. 
Distance of ven- 
trals from 
snout equals 
distance from 
their inser- 
tion — 
Caudal 
fin con- 
tained in 
head. 
Width of 
lower jaw 
(cartilage) in 
head. 
Bows of 
papillae 
across 
symphysis 
of lower lip. 
Papillae on 
lower lip in 
oblique row 
from corner 
of mouth. 
P. lahonton..- 
Plat .... 
81 to 96 
45 to 50 
To tip of middle 
caudal rays. 
1.2 
3. 5 to 4, mar- 
gin convex. 
4 
10 
P. generosus .. 
Convex. 
77 to 87 
41 to 45 
To middle of 
middle caudal 
rays. 
1 
3 to 3. 7, mar- 
gin nearly 
straight. 
2 
7 
Found in abundance in Susan River, and also in Little Truckee River and Prosser Creek. 
Types (No. 50587, U. S. Nat. Mus.) from Susan River, collected by Rutter and Chamberlain. 
