PLATE XXIV. Fig. 2.
_A. olivaceus, punctis fuscis minutissimis irroratus; lateribus vittâ
longitudinali argenteâ: maxillâ inferiore longiore._
B. 3; D. 12; A. 2/13; C. 16, &c.; P. 18; V. 7.
LONG. unc. 3. lin. 10.
FORM.—A much smaller species than the last, but the general form
similar. Rather more elongated, the depth being contained seven and
a half times in the length. Head one-fifth of the length measured to
the base of the caudal fork. Snout a little longer, and more
pointed. Lower jaw at all times a little the longest. Teeth similar,
and similarly disposed. Nostrils similar; but no pores on the crown,
or only one on each side, and that not very distinct. All the fins
similar.
COLOUR.—Not noticed in the recent state. In spirits it appears of a
uniform greenish or olivaceous brown, the back and sides very
minutely dotted with darker brown. There is a pale silver band along
the middle of the side, not bounded, however, by any definable line,
but shading off insensibly into the brown above and below. The
irides are still bright, and appear to have been golden.
Habitat, Goree Sound, Tierra del Fuego.
There are three specimens of this second species in the collection, all
of the same size, and not differing in any respect from each other,
except that one of them has thirteen rays in the dorsal fin, and
fourteen soft rays in the anal. Mr. Darwin’s notes state that they were
taken at Goree Sound, Tierra del Fuego, in the mouth of a fresh-water
stream, where the water was quite fresh; and that when put into salt
water they immediately died.
The silver band at once distinguishes this elegant species from the
last, independently of its smaller size. The specimens appear full
grown.
There is the same peculiarity with respect to the anal and sexual
orifices in this species, as in the one previously described.