60 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
The affinities of this genus with Cottopsis have already been alluded to above. From the 
marine genera it differs by well marked characters, one of which is the preopercular spiny 
process and its rather small anterior dorsal fin. The upper aspect of the head is smooth, as in 
Leiocottus, and partly also as in Scorpaenichthys , hut it has none of the cutaneous flaps which 
the latter is provided with. 
LEPTOCOTTUS ARMATUS, Grd. 
Plate XV, Fig. 2. 
Spec. Char. —Head much depiessed ; upper jaw longer than the lower ; posterior extremity of maxillary extending some¬ 
what beyond the vertical of the posterior rim of the orbit. A preopercular process provided with three spines directed upwards. 
Blackish brown above ; whitish beneath ; dorsals, caudal, and pectorals yellowish, barred with black ; anterior dorsal with a 
black s>.ot posteriorly. Ventrals and anal whitish. 
Svn.— I.eplocoltus armatus, Grd. Proc. Acad.Nat. Sc. Fhilad. VII, 1854, 131 & 145 ; &, VIII, 1856, 133. 
Acanthocotlus inermis, Ayres, MSS. 
The general physiognomy of this species is quite peculiar by its head and anterior portion of 
the body being broader thin deep; at the origin of the first dorsal the depth is equal to the width, 
the latter diminishing more rapidly backwards than the former, so as to measure considerably 
less. The head forms a little less than the third of the whole length ; its upper surface is very 
much depressed, and grooved upon its middle. The snout is broad and flattened, the upper jaw 
protruding over the lower one. The mouth is broad and rather large ; the posterior extremity 
of the maxillary extending somewhat beyond a vertical line drawn across the posterior rim 
of the orbit. The anterior and tubular nostril is nearly midway between the margin of the 
upper jaw and the anterior rim of the orbit. The eyes are of medium size, and partly situated 
on the upper surface of the head ; their shape is sub-elliptical, and their longitudinal diameter 
comprised about six times and a half in the length of the sides of the head. A stout and 
horizontal process may be observed upon the convexity of the preopercle, and terminated by 
three acute and hook-like spines curved upwards. Another process, small and obtuse, exists 
beneath upon the inferior limb of the same opercular bone. The head otherwise is smooth ; the 
bones of the scull slightly perceptible, the middle sub-orbital inconspicuous, and the opercle 
margined by a loose membrane. The isthmus is broad ; its width is contained nearly four times 
in the distance extending between its angle and the extremity of the lower jaw. The branchi- 
ostegals are well developed, and six on either side. 
The first dorsal fin is lower than the second, and much longer than high ; its upper margin 
forms a convex curve ; it is composed of seven or eight slender spines, the third and fourth of 
which being the highest. The origin of that fin meets a vertical line drawn immediately behind 
the superior portion of the insertion of the pectorals. The second dorsal is nearly contiguous to 
the first at its base ; it is composed of seventeen or eighteen slender and undivided rays, 
gradually diminishing in height posteriorly from the fifth, which is the highest. The caudal 
is slender and sub-truncated, constituting a little less than the seventh of the entire length, and 
composed of nine bifurcated rays, two simple ones, and a few rudiments above and below. The 
origin of the anal takes place nearly opposite the fifth ray of the second dorsal, extending 
posteriorly as far as the latter; its terminal rays, mayhap, projecting a little further backwards. 
Its shape is the counterpart of the second dorsal, but not quite so deep as the latter is high ; it 
is composed of sixteen or seventeen slender and undivided rays, the membrane intervening 
which being slightly emarginated. The vent is situated at a short disstance from the anterior 
