PLATE XVIII. Fig. 2.
FORM.—Body elongated and compressed; the depth, which varies but
little, one-sixth of the entire length; thickness in the region of
the pectorals rather more than half the depth. Head contained very
little more than four times in the length. Profile sloping but very
little. Snout rather short: mouth protractile, and rather wide: lips
somewhat fleshy and reflexed. Gape reaching to beneath the anterior
part of the orbit, but the maxillary, which is dilated at its
posterior extremity, and cut nearly square, reaching to beyond the
middle. Lower jaw a little the longest, and ascending to meet the
upper. Several rows of sharp velutine teeth in each jaw, with some
here and there stronger and more hooked than the others, those below
almost fine card: a band on the vomer and on each palatine. Tongue
of a triangular form, free and pointed at the tip, with a ridge of
asperities down the median line. Eyes high, but hardly interrupting
the line of the profile; their diameter one-fifth the length of the
head; distant one diameter from the end of the snout. No filamentous
appendages of any kind on any part of the head; but an irregular
circle of pores nearly surrounding the orbit; also a few very
distinct pores beneath the lower jaw. Preopercle rounded, with
distant pores along the margin. Opercle terminating posteriorly in a
sharp salient angle with the basal margin ascending; beneath which
the subopercle and interopercle are both very distinct. Branchial
membrane free and open all round, not adhering to the isthmus
underneath, but deeply notched in the middle.
The dorsal commences in a line with the posterior point of the
gill-cover, and is very similar to that of _Clinus_. Spinous
portion long, and, excepting the first two rays, of nearly uniform
height, equalling nearly half the depth; the membrane deeply
notched between the spines, the tips of which are invested with
filamentous tags. Soft portion of the dorsal more elevated than
the spinous, and with only four rays. Between the end of this fin
and the caudal is a small space equalling nearly two-thirds of the
depth beneath. The anal commences under the twelfth dorsal spine,
and exactly corresponds to the posterior half of that fin,
reaching also to the same point. The spines in both fins are sharp
and moderately strong; the soft rays articulated and branched, and
terminating rather in a point behind. Caudal rounded, with
fourteen branched rays, and a few shorter simpler ones. Pectorals
one-seventh of the entire length, rounded when spread open, with
all the rays except the last branched. Ventrals narrow and
pointed, about the same length as the pectorals, and inserted but
very little in advance of those fins: the spine well developed,
and half the length of the soft rays: first soft ray long, and
deeply divided so as to appear like two; the second ray slender
and shorter.
Body covered with very minute scales; but none on the head or on any
of the fins. Three very distinct lateral lines, with a portion of
a fourth, as already stated above.
B. 6; D. 20/4; A. 9/4; C. 16, &c.; P. 17; V. ½.
Length 3 inc. 8 lin.
COLOUR.—Not noticed in the recent state. _In spirits_ it appears of a
nearly uniform bister brown, with the fins and some portion of the
head darker than the rest, especially a blackish spot on the
opercle.
Habitat, Bay of Islands, New Zealand.
There are four specimens of this new fish in the collection, all similar
except in size. The above is the largest. The others measure in length
from one inch and three quarters, to not quite three inches. The two
largest are from the Bay of Islands, New Zealand. The other two have
lost their labels: I only presume therefore that they are from the same
locality.
TRIPTERYGION CAPITO. _Jen._
PLATE XIX. Fig. 1.
_T. fusco-griseum, pinnis concoloribus: tentaculis palpebralibus
duobus parvis gracilibus e crinibus duobus vel tribus formatis;
nasalibus minutis simplicibus: dorsali primâ humili sex-radiatâ,
radiis subæqualibus; secundâ duplo altiore; tertiâ parum altissimâ:
lineû laterali abbreviatâ, vix ultrà pectorales extensâ._
B. 6; D. 6—20—14; A. 25; C. 14, &c.; P. 16; V. 2.
LONG. unc. 2. lin. 5.
FORM.—Depth at the pectorals one-sixth of the length: thickness at the
same part about two-thirds of the depth. Head rather large, thicker
than the body, contained four and a half times in the entire length.
Snout short, the profile falling very abruptly from between the
eyes. These last large, one-third the length of the head, high in
the cheeks, reaching to, but hardly interrupting, the line of the
profile. Above each a short slender compound tentacle: that on the
right side consists of two filaments, one simple, the other forked,
so as to appear like three; that on the left appears undivided. Also
a minute filament at each nostril. The maxillary reaches to beneath
the middle of the orbit. Jaws equal: in each a row of small conical
sharp-pointed teeth, with a broad velutine band behind, the band,
however, only in front. A transverse band of velutine teeth on the
vomer, extending a little on to the palatines. Opercle and
preopercle rounded. Branchial membrane free all round, with a
shallow notch in the middle underneath.
The first dorsal commences in a vertical line with the insertions of
the ventrals; the rays are six in number, and so nearly equal in
length as to cause the fin to appear quite even; its height is
scarcely more than one-third of the depth. The second dorsal
begins a little behind the origin of the pectorals: it is also
nearly even, but twice the height of the first. The third closely
follows the second: this fin is uneven, but its most elevated
point is somewhat higher still than the second. The rays of the
first and second of these fins are spinous: those of the third
soft and articulated, but all simple. The anal, which has also
simple rays, commences beneath the middle of the second dorsal,
and terminates in the same vertical line with the end of the
third, between which last and the caudal is a small space. Caudal
square, with twelve of the principal rays branched. Pectorals a
little less than one-fourth of the entire length; the ninth and
tenth rays longest; the six lowermost rather stouter than the
others, and, as well as the three uppermost, which are very
slender, simple; the fourth to the tenth, both inclusive,
branched. Ventrals contained about six and a half times in the
entire length; consisting of only two slender filamentous rays.
Scales minute, their free edges finely ciliated; the concealed
portion of each scale marked with twelve or fourteen striæ. The
lateral line rises at the upper angle of the opercle, and is well
marked by a row of tubular scales till it reaches a little beyond
the extremity of the reclined pectoral, where it abruptly
terminates, and all further trace of it is lost.
COLOUR.—(_In spirits._) Of a nearly uniform dark brown, inclining to
griseous, with some appearance of darker clouds or spots between the
second dorsal and the lateral line; this last also is indicated by a
darker streak than the ground colour. Fins dark brown: there is,
however, some trace of a white edging to the anterior half of the
anal, which may have been more conspicuous in the living state.
[Illustration:
_Fish. Pl. 19._
_Waterhouse Hawkins del._
]
_1. Tripterygion Capito._
_2. Gobius lineatus._
_2a._ „ „ _dorsal View._
_3. Gobius ophicephalus._
_3a._ „ „ _dorsal View._
A _second specimen_ slightly differs from the above, but is evidently
referable to the same species. It is smaller; and the profile falls
more gradually. The caudal has only eight branched rays, with two
lateral simple ones. The pectorals have the tenth and eleventh rays
longest, with the seven lowermost (instead of six) stouter than the
others and simple. The fin-ray formula is also different.
D. 6—19—13; A. 25; C. 10, &c.; P. 17; V. 2.
Length 2 inc. 1 line.
The colours are paler, and more decidedly grey, with the darker
motlings more distinct. The dorsals and caudal are pale, minutely
dotted with brown. Tips of all the anal rays white.
Habitat, Bay of Islands, New Zealand.
This species approaches very closely the _T. nigripenne_ of Cuvier and
Valenciennes, of which it may possibly be a variety; but the description
in the “Histoire des Poissons,” as regards the form, is limited to a
very few words. If the figure given by those authors be correct, the _T.
nigripenne_ differs decidedly in the first dorsal being more elevated,
with the rays more unequal, and in the lateral line extending the whole
length of the fish. In the present species the first dorsal is low and
even, with the rays all equal, and the lateral line cannot be traced
much beyond the pectoral; and these characters are found in both
specimens. There are also six rays in the first dorsal. According to the
description, the _T. nigripenne_ has but five, though six are
represented in the figure.
From the _T. varium_, this species differs not only in its fin-ray
formula, but in its markings: and the same characters serve to separate
it still more widely from _T. Forsteri_ and _T. fenestratum_.
This species was obtained by Mr. Darwin on tidal rocks in the Bay of
Islands, New Zealand. Three out of the only four extra-european species
described by Cuvier and Valenciennes come from the same locality.