156 
U. S. P. E. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
and so closely approximated that the interocular space consists of a mere hony ridge ; they are 
situated on the left side, and their horizontal diameter is contained four times in the length of 
the side of the head, somewhat less than once in advance of the anterior rijn of the orbit. 
The origin of the dorsal fin takes place near the nostril, on the right side of the anterior rim 
of the upper orbit; its rays are gradually increasing in height to near the posterior third of the 
extent of that fin, to diminish again rather rapidly backwards. It terminates near the base of 
the caudal without being contiguous to it. The anal commences on a line situated posteriorly 
to the base of the pectorals, and terminates almost evenly with the dorsal; its middle rays 
being somewhat deeper than those of the latter fin are high. The caudal fin, which enters 
about six times in the total length, is sub-lanceolate or convex upon its posterior margin. The 
right pectoral fin is smaller than the left, which is hut moderate sized, and rather more 
tapering. The ventral fins are small also, though proportionally broad at their base or 
insertion, which is partly opposite the base of the pectorals and partly anterior. On the 
accompanying figure they are represented too much forwards. There are six hranchiostegals 
on the left side and five only on the right; the branchial aperture being continuous under the 
throat. 
Br. VI; V ; D 82 ; A 12 ; C 1, 1, 7, 6, 1, 1; V6; PI, 10. 
The only rays that are bificated or dichotomised may he observed in the caudal and left 
pectoral. The scales are of moderate size, longer than deep, sub-elliptical, and finely 
pectinated upon their posterior margin ; their anterior section exhibiting radiating grooves. 
They cover the opercular apparatus and cheeks, extending likewise to some of the fins. The 
lateral line takes nearly a straight course from the suprascapular region to the base of the 
caudal, it being but slightly raised anteriorly. The ground color is of a soiled yellow ; the 
scales being margined and the fins speckled with blackish. 
Beference to the figures .—Plate XLb, fig. 1, represents the left side of Psettichthys sordidus, 
size of life. Fig. 2 the right side of the same. Figs. 3 and 4 are scales of the lateral line 
from either side ; the other scales were not preserved on the specimen. 
•Specimens from Presidio exhibit upon their body and fins irregular small black spots, in 
addition to the color elsewhere alluded to. 
List of specimens. 
Catal. 
No. 
No. of 
spec. 
Locality. 
When 
collected. 
Whence obtained. 
Nature of 
specimens. 
Collected by— 
702 
i 
San Francisco, Cal_.. 
1853 
Lt. A. W. Whipple 
Alcoholic. 
Dr. C. B. Kennerly__ 
611 
4 
Coast of California 
1853 
Lt. W. P. Trowbridge_ 
_do_ 
Lt. Trowbridge_.... 
703 
12 
Tomales bay, Cal___ 
1855 
Mr. E. Samuels_ 
E. Samuels..___ 
