In addition to the investigation of these several mail-cheeked fishes it has been found necessary
to carefully examine certain special features in th e cranial anatomy of several other fishes, these fishes
being mostly obtained here, though certain of them were sent me from America, by one of my assistants,
Mr. Wm. F. Allen.
The Scorpaenidae are said by Gill to be the most generalized of the mail-cheeked fishes, and the
Scorpaenids to be the most generalized of th a t family. Because of this, I begin th e descriptions with
Scorpaena, selecting S. Scrofa because of its being larger th a n S. porous. This fish is described with
considerable detail, for it is often th e apparently unimportant features th a t are important in comparisons.
Each cranial bone is described under its own special heading, and to make th e descriptions
complete under each of these headings, some repetition has been unavoidable. As th e descriptions
proceed, comparisons are a t once made with fishes other th a n th e mail-cheeked ones, no special sections
being devoted to comparative discussions alone. The other mail-cheeked fishes included in the
investigation, are, when described, compared, as much as possible, with Scorpaena scrofa only.
Scorpaena porcus, the skull of which, though smaller th a n S. scrofa otherwise closely resembles it, is
referred to only where appreciable differences were noticed.
The nomenclature employed differs somewhat from th a t heretofore employed by me, for it has
seemed to me best to adopt, in large part, th e current English names of th e cranial bones. This will
appear in the descriptions of Scorpaena, and needs no special explanation here.
During the investigation, which has been in progress during several years, I have had th e continued
aid of my three assistants a t Menton, Mr. Jujiro Nomura, Mr. G. E. Nicholls and Mr. John
Henry, to whom the preparation of the material, the drawings used for illustration and th e literature
references were largely confided, circumstances obliging me to be frequently absent from th e laboratory.
The dissections were almost all prepared by Mr. Henry. Mr. Henry also traced the nerve components
in the sections of D actylopterus, controlling also certain of th e results obtained b y me in th e examination
of the sections of Scorpaena and Lepidotrigla. The drawings were made by Mr. Nomura
from specially prepared specimens, n o t used for th e descriptions, and because of frequently
occurring individual variations in different specimens the figures will be found to differ in certain
details from the descriptions. The descriptions give th e usual conditions.
When the work was nearly finished I received Supino’s (’04/06) work on the Triglidae, in which
Scorpaena scrofa, Sebastes, Trigla lyra, Cottus, Peristedion and Dactylopterus are all described and
figured. B ut both th e descriptions and th e figures are so incomplete and so lacking in definite detail
th a t b u t little reference will be made to them. Garman’s (’92) figure of Cottus octodecimospinosus,
given in his work on ,,The Discoboli“, is equally indefinite and unsatisfactory.
I. THE LORICATI .
I. Scorpaena.
t. S K U L L .
The complete skeleton of the head, and the skull proper (neurocranium) of Scorpaena scrofa
are show in Figs. 1—9. As is well known, th e orbits are large; the interorbital wall simple; the dorsal
surface of th e skull, between th e orbits, deeply concave and traversed longitudinally by two prominent
ridges; and on the vertex there is a subquadrangular groove which is slightly broader than it is long,
and which is bounded on either side, and both anteriorly and posteriorly, by ridges.
The two longitudinal ridges between the orbits mark the course, on either side of the head, of
the supraorbital latero-sensory canal. Each of these ridges turns postero-laterally a t its hind end
and is there joined by th e transverse ridge th a t forms the anterior boundary of the groove on th e vertex,
the single ridge formed by these two ridges united then immediately turning posteriorly and terminating
in a pronounced spine. This spine lies not far from the hind edge of the frontal, a t the anterior
end of th e ridge th a t forms the lateral boundary of the groove on the vertex, and i t projects backward,
or backward and laterally above th e opening of th e seventh, or terminal tube of the supraorbital latero-
sensory canal, th a t opening lying immediately lateral to the lateral bounding ridge of the groove on
the vertex. Emery (’85) has called this spine the frontal spine, naming it after the bone on which it
lies, and I adopt this term ra the r th an the term tympanic, given b y Jordan & Gilbert (’83) to the
corresponding spine in Scorpaena porcus.
The tympanic spine of th e Scorpaenidae, as defined by Eigenmann and Beeson (’94) in their
descriptions of th e Sebastinae, is said to always overarch a mucous pore, to always lie near the outer
border of the frontal, and to be always present and homologous throughout the group. The coronal
spine, as defined by the same authors, is said to be developed in b u t few species, to lie on the frontal,
nearer the mid-dorsal line th a n the tympanic, and directly in front of the parietal ridge. The frontal
spine of Scorpaena scrofa thus has the relations to the supraorbital latero-sensory canal of a tympanic
spine, while in other respects it has the position of a coronal spine, as th a t spine is shown both in Jordan
& Gilberts’ diagram of the cranial ridges of Sebastodes (1. c. p. 653) and in Cramer’s (’95) figures
of Sebastodes introniger and Sebastodes auriculatus. The relation to the supraorbital canal is,
however, so typical th a t the spine, in Scorpaena, is certainly a tympanic and not a coronal one. I t
lies a t the hind end of the interorbital ridge on th e frontal, th a t ridge thus appearing as a cranial
spinous ridge; b u t this relation of the spine to the ridge, though apparently usual in the group, is not
constant, as will appear when the spine is described in Scorpaena porcus.