FISHES. 35 
fins, is contained between five and six times in the total length; and the least depth, taken on 
the peduncle of the tail, near the base of the caudal fin, is about the third of the greatest depth. 
The greatest thickness is considerably more than half the greatest.depth. From the origin of 
the ventral the body tapers slightly anteriorly, and quite rapidly posteriorly from the anterior 
margin of both the anal and second dorsal fins. 
The head above is depressed, subconvex, and rather small. In length it constitutes about 
the two-elevenths of the whole. It is a little deeper than broad at its base. The mouth is well 
developed, the lower jaw being a little shorter than the upper, which is protractile. Several rows 
of very small and subconical teeth may be observed on the maxillaries and on the dentaries. © 
The palate is perfectly smooth, or without teeth. The pharyngobranchials, upper and lower, 
are densely covered with card-like teeth. The tongue is smooth and narrow, and of but me- 
dium development. The posterior extremity of the upper maxillary does not quite extend to a 
vertical line which would pass through the anterior rim of the orbit. The nostrils are very 
small, the anterior one being the smallest, and both of them are nearer to the anterior rim of 
the orbit than to the lip of the upper jaw when the latter is in its retracted position. The eye, 
though well developed, is small when compared to other species, circular in shape, and its 
diameter contained nearly five times in the length of the side of the head. Its upper margin 
approximates the line of the profile. The opercular apparatus is rounded, and convex upon its 
margin. Conspicuous scales cover its upper margin as well as the cheeks. On the remaining 
portion of the opercle, and the sub and interopercles, scales are apparently wanting, owing to 
the transparency of the argentine membrane which passes over them. The branchial apertures 
are broadly open and continuous under the hyoidal apparatus. The branchiostegals, six in 
number, are mostly concealed under the subopercle; the innermost are flattened; the two outer- 
most, small and filiform. 
The first dorsal is quite small, and composed of slender rays. The posterior margin of that 
fin is nearly equidistant between the upper lobe of caudal fin and the extremity of the snout. 
The second dorsal is of moderate development, with one anterior rudimentary ray, undivided, 
like the second. The central rays bifurcate twice, with a slight indication of a subdivision of 
the third degree upon the fourth, fifth, and sixth rays. That fin is a little higher anteriorly 
than long, with its upper edge concave, and its posterior margin about half the height of the 
anterior. It is situated immediately opposite the posterior portion of the anal. The base of 
the anal is much longer than that of the second dorsal, and longer also than the depth of its 
anterior margin. Its external edge is likewise concave, and its posterior margin about two-fifths 
the height of the anterior. The first ray is rudimentary; the second is simple; the central 
ones bifurcate only twice. The caudal is deeply forked with sub-acute lobes. It constitutes the 
sixth of the entire length. Its central rays bifurcate three times, with partial indications of a 
subdivision of the fourth degree. The ventrals are altogether situated in advance of the first 
dorsal; these fins are short and broad exteriorly, when expanded. The anterior ray is the 
smallest, and remains undivided; the others subdivide three times. The pectorals are of mod- 
erate development and acute posteriorly; their ray subdividing but twice, the uppermost re- 
maining simple. They are obliquely inserted below the middle line of the body. 
Br Vis DaVile (iA NG aC, 35 LS Tabo ds, V6 P15. 
The scales are rather small, and subquadrangular in general form; sometimes a little longer 
than high, at others a little higher than long. They are posteriorly rounded, and subtruncated 
anteriorly. They constitute more than twenty longitudinal rows upon the line of the greatest 
depth of the body, and about fifteen rows on the peduncle of the tail. Small and irregular 
scales may be observed upon the base of the caudal fin. The scales on the cheeks are equal in 
development to those on the nape. On the opercular pieces they are little larger than on the 
cheeks. The ground-color is yellowish brown, minutely dotted with blackish. The dorsal 
region between the silvery bands has a darker hue than the inferior part of the flank, owing to 
