A third species of _Clupea_, in Mr. Darwin’s collection, likewise in bad
condition, much resembles in general form the common Pilchard.
Depth the same as in the Pilchard, but the head larger and longer than
in that species, being one-fourth[39] of the entire length. Abdomen
smoother; no appearance of any serratures in front of the ventrals.
Lower jaw but little advanced beyond the upper. No perceptible teeth,
more than a few very minute serratures near the lower extremity of the
maxillary. Diameter of the eye about one-fifth the length of the head.
The form and veinings of the pieces of the opercle very much as in the
Pilchard, but the interopercle more developed. The posterior margin of
the opercle and subopercle taken together is almost quite straight,
without any emargination anywhere, and not far out of a vertical; the
subopercle is cut nearly square at bottom. The preopercle is much
veined: there are also some veins on the upper part of the opercle,
and lower down on this last piece some very deep striæ, running
parallel to its junction with the preopercle, as in the Pilchard, but
still more strongly marked.
[Illustration:
_Fish. Pl. 25._
_From Nature on Stone by W. Hawkins._
_Alosa pectinata. ¾ Nat. Size.
a Magnified Scale from nape._
]
The commencement of the dorsal is very little anterior to a middle
point between the end of the snout and the base of the middle caudal
rays. The ventrals are beneath the posterior half of the dorsal as in
the Pilchard. There are the same two elongated scales on each side of
the caudal as in that species. The scales on the body, however, are
much smaller than in the Pilchard, with their free portions striated,
the basal portions marked with some irregular curved lines running in
a transverse direction towards the median line of the scale.
D. 11; A. 18 or 19; C. 19, &c.; P. 18; V. 8.
Length 10 inches 6 lines.
Habitat, Lima, San Lorenzo Island.