72 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
about three inches and a quarter in total length, the head constituting also the third of it, the 
caudal fin excluded. The occipital region is depressed, and the interocular region, which is 
broader than in the preceding species, instead of being convex, is groove-like. The rostral 
distance is gently sloping towards the extremity of the snout, exhibiting two stout and con¬ 
spicuous nasal spines, behind which is a depression for a tubular posterior nostril, the anterior 
nostril being, as usual, on the side of the snout nearer the orbit than the extremity of the ros¬ 
trum. The posterior extremity of the maxillary extending to a vertical line passing rather 
posterior to the middle of the pupil. The eye is large, sub-circular, placed towards the upper 
surface of the head ; its horizontal diameter is contained four times in the length of the sides of 
the head, not quite once in advance of the anterior rim of the orbit. A short and flattened 
tricuspid process may be observed upon the convexity of the preopercle, two of the spines 
pointing upwards, the third downwards. Upon the inferior branch of the same bone there are 
two minute spines, whilst a third one, directed forwards, is inserted upon the interopercle. 
The general disposition and structure of the fins is the same as in the preceding species ; the 
origin of the anal, however, is opposite the third ray of the second dorsal, and not as deep as 
the latter is high, and the insertion of the ventrals situated upon a vertical line intersecting the 
middle of the base of the pectorals. 
Br. V: V; D IX, 15 ; A 10 ; C 3, 1, 5, 4, 1, 2 ; V I, 3 ; P 17. 
A membranous flap may be seen upon the posterior superior rim of the orbit. The occipital 
region is provided with small spines and tubercles, symmetrically disposed, whilst the entire 
surface is spread over with small scales, similar to those of the dorsal region, with the only 
difference that the ciliated edge is less conspicuous. These scales extend over the temporal 
region, opercular apparatus, and between the orbits. The dorsal band has the same disposition 
as in the preceding species, but it is broader, though composed of a smaller number of scales ; the 
latter are more apart and their edge more strongly ciliated, or rather spinous. The lateral line 
is very conspicuous, and its curve depressed upon the middle of the flanks. 
The ground color is olivaceous, darker above than beneath. A series of four black, saddle- 
like spots, may be observed along the back—the first one across the anterior dorsal, the second 
and third over the second dorsal, and the fourth upon the peduncle of the tail, between the two 
fins. The lower half of the sides, below the lateral line, is ocellated with dull white or yellow. 
The inferior surface is unicolor. The fins are unicolor, of the general hue of the region to which 
they respectively belong. 
References to the figures .—Plate XXII b, fig. 5, represents Artedius notospilotus , from San 
Francisco, California, and size of life. Fig. 6, a dorsal scale-like shield, magnified. 
List of specimens. 
Corresponding No. 
of 
No. of specimens. 
Sex and age. 
Locality. 
When collected. 
Whence obtained. 
Original number. 
Nature of specimens. 
Collected by— 
1 
1856... 
E. Samuels. ---- 
Alcoholic.. 
E. Samuels- 
1 
1 &>* 
1857... 
Dr. Ayres_-_-_ 
36 
_do- 
Dr. Ayres- 
l 
July, 1856 
Capt. Murden___ 
Capt. Murden. 
1 
