FISHES OF STREAMS TRIBUTARY TO MONTEREY BAY. 
65 
of fin slightly concave. First anal ray 1.3 in head; edge of fin concave. Ventrals rounded, not reach- 
ing anal. Pectoral equal in length to height of dorsal; obtusely pointed. Caudal deeply cleft, the 
lobes acutely rounded. 
Color in spirits dusky above, light beneath, the sides and under parts silvery; a narrow, light stripe 
extending from upper edge of gill opening to base of caudal; beneath this a conspicuous black stripe, 
narrow in front, somewhat wider behind, the color deepest above anal fin; several very indistinct, narrow, 
dark stripes beneath lateral line. 
The scales are more or less quadrangular, rounded or spatulate in shape. (Fig. 5-10, pi. xxi and 
XXII.) The basolateral angles are prominant, and the apicolateral angles weak or entirely obliterated. 
There are no basal radii, and lateral radii are rarely present except in specimens from the Russian River. 
The apical radii number from 8 to 21, usually 10 to 18. There are from 50 to 61 scales in the lateral 
line, counts of a series of specimens resulting as follows: 
Scales lateral line 
50 
51 
52 
S 3 
54 
SS 
56 
57 
58 
59 
60 
6r 
Number of specimens 
I 
6 
4 
6 
14 
28 
26 
22 
15 
20 
13 
3 
In this character it differs from H. symmetricus , which has from 47 to 53. It differs further from the 
same species in having smaller eyes and a shorter head. Measurements of many specimens have been 
made and published. “ 
At least one isolated basin, the Russian River, is included in the region occupied by this form, 
and specimens from it are somewhat peculiar. The trim, slender form characteristic of the species 
reaches its highest development here, and the scales usually have from i to 5 lateral radii. (Fig. 10, 
pi. xxn.) Specimens from Napa River also show slight local peculiarities, but neither these nor those 
from the Russian River appear to differ very much from individuals from the streams flowing into San 
Francisco Bay. 
H. venusius appears to be the parent form of H. navarroensis and H. parvipinnis, they having become 
differentiated through the agencies accompanying complete isolation. It will be noted on referring to 
the descriptions of these species that lateral radii are present on the scales of both, and that in this respect 
they resemble individuals of H. venusius from the Russian River. The distribution of H. venusius in 
the Sacramento basin is unknown. 
Hesperoleucus navarroensis, new species. Navarro roach. 
This is a species inhabiting the Navarro Basin on the western coast of northern California. It is 
distinguished by its robust body, deep caudal peduncle, short snout, and rounded fins, and in having 8 
rays in the dorsal and anal fins. This form is closely allied to H. parvipinnis , tlie one evidently derived 
from the other or both from one parent stock. H. navarroensis differs from H. parvipinnis in the number 
of anal fin rays and in having generally i less row of scales above the lateral line. 
Description of the type, no. 74477, United States National Museum, from Navarro River near Philo, 
Cal. Length 90 millimeters. 
Head 3.6 in lengtli to base of caudal; depth 3.6; depth caudal peduncle 2.2 in head; eye 4.2; inter- 
orbital area 2.8; snout 3.1; dorsal rays 8 ; anal rays 8 ; scales lateral line 56 ; between lateral line and middle 
of back 13; between lateral line and origin of ventral 7; between occiput and origin of dorsal 30. 
Body deep, particularly in the caudal region; posterior margin of eye behind a median vertical 
through head; lower border of eye somewhat below median line of body. Gilhakers on first arch 8, 
very short and stumpy. Pharyngeal teeth (cotypes) 4-5, 4 on the right side; a grinding surface equal 
to width of tooth; the tips slightly hooked. No material variation appears in the teeth of a number of 
c Snyder, J. O.: Op. cit., Bulletin Bureau Fisheries, vol. xxvn, 1907, p. 176; Notes on the fishes of streams flowing into 
San Francisco Bay, Appendix to Report Commissioner of Fisheries for 1904, p. 332, Rutilus symmetricus* 
