_Serrani formam quam maximè gerens. Pinna dorsalis unica, per totam
longitudinem subæqualis. Membrana branchialis septem-radiata. Nec
fovea, nec pori, infrà symphysin. Dentes maxillares velutini, serie
externâ cæteris fortiori, paucis, hic illic sparsis, subcaninis;
palatini nulli. Preoperculum denticulatum. Operculum mucronibus
tribus posticè armatum. Spina analis secunda fortis. Squamæ corporis
ciliatæ; minutissimæ inter radios pinnarum verticalium, in seriebus
dispositæ._
[Illustration:
_Fish. Pl. 9._
_W. Hawkins del^t._
]
_Fig. 1._ _Prionodes fasciatus._
_2._ _Stegastes imbricatus._ _Nat. Size._
I am called upon either to establish this new genus among the
_Sciænidæ_, or to break down one of the essential distinctions set by
Cuvier between this family and the _Percidæ_. The form is so completely
that of a _Serranus_,—which it resembles especially in its dorsal fin,
head, maxillary teeth, form and armature of the pieces of the
gill-cover, and in the arrangement of the scales on the body,—that at
first sight no one would hesitate to refer it to that group; but _the
vomer and palatines are without teeth_.[21] In this respect, indeed, I
consider it an important discovery; as it affords another striking
instance of the uncertainty of this character, in cases in which others,
which have been generally made subordinate to it, remain constant. It is
probable that the time will come, when it will be found necessary to
revise some portion of the _Percidæ_ and _Sciænidæ_ with reference to a
more correct valuation of this character. For the present, however, I
refrain from interfering with the Cuvierian arrangement; and the only
alternative is to consider this as a new form among the _Sciænidæ_,
where it must be placed along with those genera possessing one dorsal
fin, and having seven rays in the branchiostegous membrane. Such are
_Hæmulon_, _Pristipoma_, and _Diagramma_; from all which, however, it is
at once distinguished by the absence of pores at the symphysis and on
the lower jaw, and by the much more developed spines on the opercle, and
from _Pristipoma_ by its having, further, scales on the vertical fins.
On the whole, it seems to approach nearest to _Hæmulon_; but the crown
and snout are more free from scales than in that genus, and the scales
on the body are not set in oblique rows, as is the case in so many of
the true _Sciænidæ_. The head also has no cavernous appearance about it.
This new form is from the Galapagos Archipelago.