of this p a rt of th e skull, lying between th e nasal above, th e mesethmoid and th e cartilage of th e
snout mesially and below, th e ectethmoid posteriorly and below, and th e anterior palatine process
of th e ethmoid cartilage anteriorly. The p it is n o t large enough to lodge th e entire nasal sac, a p a rt
of th e sensory portion of the sac extending laterally, beyond th e lateral edge of th e skull, onto th e
dorsal surface of th e palatine, and there lying between th e palatine and lachrymal bones. A mesial
diverticulum of the sac, corresponding to th a t in Scorpaena b u t somewhat differently disposed, runs
forward and mesially. through th e passage th a t leads from the nasal p it into th e rostral depression,
and then tu rn s mesially behind th e rostral, between it and the anterior end of th e mesethmoid, and
abuts against b u t is apparently n o t continuous with its fellow of th e opposite side.
The nasal bone is traversed b y th e supraorbital latero-sensory canal, and lodges one organ
of th a t line, th e anterior opening of th e canal lying a t th e extreme antero-lateral corner of th e bone.
De Sède de Liéoux (’84, p. I l l ) says th a t th e cephalic portion of th e latero-sensory canals is absent
„chez les Trigles“ , Trigla hirundo being th e species particularly examined. This is far from being
true, as will appear in th e course of my descriptions.
The VOMER has ascending processes which are in contact, posteriorly, with th e anterior end
of th e th in perichondrial layer of th e mesethmoid. The ascending processes of opposite sides enclose
between them, as in Scorpaena, th e anterior portion of an internasal ridge of cartilage, th e bone and
cartilage here being, in medium-sized specimens, raised into a slight ridge, while in large specimens
th ey become a prominent knob with a flat summit. The cartilaginous rostral slides backward and
forward on this ridge or knob. The lateral corner of th e ascending process of th e vomer is slightly
raised and embraces th e anterior edge of th e base of th e anterior palatine process of th e ethmoid
cartilage; this raised or process-like portion of the vomer of Trigla corresponding strikingly, in position,
to th e septomaxillaries of Sagemehl’s figures of th e Cyprinidae. Antero-mesial to this little process
there is a rounded eminence, prominent in large specimens, near th e anterior edge of th e dorsal surface
of th e bone. The lateral surface of this eminence, and th e slight hollow between it and th e palatine
process, give articulation to the ventral edge of the ascending process of th e maxillary, a pad of tough
fibrous or semi-cartilaginous tissue lying between the two surfaces.
The ventral surface of th e convex anterior edge of th e vomer is slightly raised, and is furnished
with an uninterrupted band of small villiform teeth. Immediately posterior to the lateral end of th is
band of teeth, there is a large depression which gives insertion to the very slightly developed vomero-
palatine ligament. A slightly developed lateral process projects postero-laterally, extending beyond
th e anterior edge of the ventral plate of th e ectethmoid and there lying upon the ventral surface of
th a t plate.
In Trigla lineata th e anterior end of th e vomer is b en t abruptly, though b u t slightly, downward ;
and although this is a n atural formation, it has decidedly th e appearance of having been produced by
a blow on the end of th e snout of th e fish.
The PREMAXILLARY has a broad oral surface, covered its full length with small villiform
teeth. A t about the middle of the length of th e bone, there is a thin flat postmaxillary process directed
backward and slightly upward. This process forms th e hind end of a pronounced longitudinal ridge
on the internal surface of th e bone, this ridge representing a thickened p a rt of th e bone, of membrane
origin, which lies slightly dorsal to its tooth-bearing portion. This membrane component of th e bone
has a thin, flat and rounded hind (distal) end, which forms the postmaxillary process of the bone, and
a thickened anterior (proximal) end which, in my large specimens, forms a marked eminence on 'th e
an te n o r end of the entire bone, th e eminence being round in outline and having a flat summit. This
flat surface is presented toward a similar surface on its fellow of the opposite side, and is bound to th a t
fellow by a short strong ligament. The dorso-posterior corner of the eminence is in contact with the
ventro-anterior corner of th e rostral. The bone has ascending and articular processes, more or less
fused to form a single large process which rises from the membrane component of th e bone. The
ascending process is shorter and stouter th an in Scorpaena, being b u t little if any longer th an the
•articular process. I t lies upon and is firmly bound to the dorsal surface of the rostral, and between
it and its fellow of the opposite side there is a deep V-shaped groove, as in Scorpaena. The articular
process gives articulation to the maxillary in exactly the same manner th a t the corresponding process
does in Scorpaena, and here, as there, a pad of semi-cartilaginous tissue lies between th e articulating
surfaces.
The MAXILLARY has an anterior, articular end, strictly comparable to th a t of Scorpaena,
b u t the middle portion of th e shelf-like ligamentary process of th a t fish is wanting here, as it is in
Cottus. This is doubtless due to the fact th a t, in both Trigla and Cottus, the anterior end of th e lachryma
l has not th e strong attachment to the maxillary th a t it has in Scorpaena, th e lachrymal, in
Trigla, projecting above and beyond the maxillary without coming into contact with it. The maxil-
la ry process of the palatine articulates with the dorsal surface of the maxillary, as in Scorpaena, the
articulation taking place in a depression, which lies in the angle between the ascending process and
th e shank of th e bone. The extreme proximal end of th e bone lies along and is bound by tissue to
th e ventral surface of th e rostral. The bone articulates by the dorso-posterior portion of its
ascending process, and through the intermediation of a pad of fibrous or semi-cartilaginous tissue,
with th e lateral surface of th e eminence, already described, on the dorsal surface of the ascending
process of th e vomer. On the internal surface of the bone, beginning opposite its ascending process
and extending distally somewhat beyond it, there is a flat shelf-like ridge, the distal end of which
is enlarged and gives insertion to a large tendon of th e superficial division, Al5 of th e adductor
mandibulae muscle, th a t tendon having its insertion, in Scorpaena, in a slight depression in this
same p a rt of th e maxillary. The maxillo-mandibular ligament has its insertion, together with a
small tendon of the superficial division, A of the adductor mandibulae, and also with a tendon of
th e deeper division, A2A3, of th a t muscle, on a ridge-like eminence on the dorsal surface of the
maxillary, this eminence thus replacing the distal end of the ligamentary process of Scorpaena. The
ethmo-maxillary ligament is inserted on the base, or sometimes even near the summit of the ascending
process.
The cartilaginous ROSTRAL is broader th an in Scorpaena, and th e median portion of its
posterior half, alone, has sliding contact with the dorsal surface of the snout. This surface of contact
is relatively wide and is usually slightly concave, b u t in some specimens it is flat or even slightly
•convex, conforming in this to the much flattened dorsal surface of the snout of the fish. The dorsal
•surface of the cartilage is conical, or pyramidal, sloping upward from all sides toward a central point.
The ascending processes of the premaxillaries rest upon the anterior half only of this surface, the
posterior portion being exposed. Immediately dorso-posterior to the ascending processes of the
premaxillaries, on the central point of the cartilage, there is a mass of tough fibrous tissue from which,
•on either side, the rostro-palatine ligament has its origin. These ligaments do n o t form a continuous
¡band crossing the middle line of the head, as in Scorpaena, and they are not, as in th a t fish, in contact