56 
17. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
Leptocottus. From the former it differs by the presence of teeth on the palatine hones and the 
absence of maxillary barbels ; from the latter by the continuity of the gill openings, the inser¬ 
tion of the ventrals ; and, finally, from both, as well as from all the genera of this family, by 
the structure of the anal fin, the three anterior rays of which are stouter, more developed, and 
somewhat isolated from the rest, especially in the male sex. 
1. OLIGOCOTTUS MACULOSUS, Gird. 
Spec. Char.— Head sub-conical. Mouth moderately cleft; posterior extremity of maxillary extending to a vertical line 
intersecting the pupil. A stouiish bicuspid process on the convexity of the preopercle. Two acute nasal spines. Dorsal fins 
contiguous. Origin of anal in advance of the anterior margin of second dorsal. Yellowish brown above, mottled or variegated 
with blackish ; along the dorsal legion a series of blotches of a deeper hue; lower half of sides vermiculated. Abdomen of 
a bright saflron hue in the male. Inferior surface of head with traces of black markings ; throat and abdomen unicolor, as also 
the ventrals and anal. Dorsals, caudals, and pectorals transversely barred. 
Svn. —Oligocotlus maculosus, Grd. Pro. Acad. Nat. Sc. Philad. VIII, 1856, 133 ; &, Journ. Bost. Soc. Nat. Hist. VI, 1857. 
Plate xxiv, Fig. 7. 
Among all the specimens which we have examined, none attained an absolute size of three 
inches ; and what gives us to think that we deal with adult individuals is the fact that the 
females are full of ripe spawn, and both sexes clothed with the brilliant hue peculiar to that 
eventful period in ichthyic life. 
The head is but very slightly broader than deep ; its upper surface is depressed and smooth, 
the interocular space grooved, the snout very declivous, and consequently short, narrow, and 
rounded upon its periphery. The upper jaw protrudes slightly beyond the lower one ; the 
mouth is small, being but moderately cleft; the posterior extremity of the maxillaries extending 
to a vertical line intersecting the pupil. The eye is sub-circular, and its diameter contained 
four times in the length of the side of the head, exactly once in advance of its anterior rim. 
The head itself forms a little less than the fourth of the entire length. A rather stout bicuspid 
process arises from the convexity of the preopercle with its acute spines directed obliquely 
upwards. No other spines are apparent upon the opercular apparatus. We omitted, in speaking 
of the upper surface of the head, to mention two prominent and acute nasal spines ; the nostrils 
being, as usual, placed one behind, and the other beneath, each spine. The branchial apertures 
are continuous under the throat, and the branchiostegal rays six in number. 
The body is very much compressed, sub-fusiform, and deeper than broad even anteriorly. The 
anterior dorsal is lower than the posterior one, and contiguous to the latter near its base ; its 
origin is situated in advance of the base of the pectorals, and consequently close to the occiput. 
It is composed of eight slender spines nearly equal in height, giving the outline of the fin the 
appearance of a depressed curve. Its base is somewhat more than the half of that of the second 
dorsal. The latter is composed of sixteen or seventeen slender and undivided rays, diminishing 
slightly in height from the second backwards, the first ray being a little shorter than the 
second. The extremities of the posterior rays do not quite reach the base of the caudal. The 
caudal fin is slender and proportionally well developed ; it constitutes a little less than the 
fifth of the total length, being comprised three times on the space between its base and the 
thoracic belt. The origin of the anal fin is situated a little in advance of the anterior ray of 
the second dorsal, composed of thirteen undivided rays, the three anterior of which being deeper 
and stouter than the rest, particularly in the male, where they project beyond the general 
outline of the fin. The interradial membrane is deeply emarginated. The extremities of the 
posterior rays do not extend so far back as those of the dorsal opposite. The ventrals are 
