organs, there thus being one more tube than in Scorpaena, th a t additional tube lying between the
fourth and fifth organs of the line. The fourth tube of the line anastomoses, in the middle line of the
head, with its. fellow of the opposite side, thus forming a frontal commissure, as in Scorpaena.
The preoperculo-mandibular canal traverses th e dentary, articular and preopercular bones,
b u t did n o t anastomose, a t its dorsal end, in th e one specimen examined, with the main infraorbital
canal : this specimen th u s differing, in this, from the specimen examined in connection with one of
my earlier works (’04). I t contains nine sense organs, three lying in th e dentary, one in th e articular
and five in the preopercular, all innervated by branches of th e mandibularis externus facialis.
Most if not all -of the primary tubes branch one to several times after they leave the bones
to which they are related and enter the cutis, but no interanastomoses of these tubes were found.
II. CRANIOMI .
I. Trigla hirundo.
1. S K U L L .
Of the Triglidae I have selected Trigla hirundo for detailed descriptions, a short separate
description being also given of Trigla lyra. The other members of the family examined are referred
to only as they differ markedly from hirundo.
The dorsal surface of the skull of Trigla hirundo consists of two portions lying a t slightly
different levels. The higher portion forms by far the larger part of the dorsal surface of the skull,
extending from the anterior ends of the nasals to the hind ends of the suprascapulars-, and being
covered, in the recent state, by a thin cutis only. The deeper portion is small, forms the dorsal surface
of the anterior end of the snout, and is covered, in the recent state, by the rostral and the dermal
and connective tissues th a t surround th a t cartilage.
The bones th a t form the larger, higher portion of the dorsal surface are all firmly bound together,
and present an even surface everywhere similarly marked with little granulations arranged
more or less distinctly in lines or ridges. At its anterior edge this part of the skull projects, eaveslike,
above the hind edge of the deeper, anterior portion, this giving to this higher part of the prepared
skull somewhat the appearance of a carapace, or, to use the expression employed by Gill in
his descriptions of Dactylopterus, a „bony casque“ . This casque-like dorsal portion of the skull
is somewhat rectangular in general outline, this being more marked in medium-sized than in large
specimens. Its anterior and posterior edges are deeply concave, and there are deep, sometimes almost
semi-circular incisures for the orbits. The mid-dorsal line is slightly convex, the amount and manner
of the convexity varying with the size of the specimen. In medium-sized specimens the mid-dorsal
line is nearly straight from its hind end to the middle of the orbits. Then it curves slightly downward
to the anterior end of the orbits, where it again becomes nearly straight, and so continues to its
anterior end. In the large specimen used for the drawings, the interorbital portion is, on the contrary,
markedly flat and straight and-is joined by slightly rounded angles to the straight anterior
and posterior portions of the surface.
The mid-ventral line of the skull is concave, and has, as the mid-dorsal line has, posterior
and anterior portions th a t are nearly straight and th a t are separated by an obtuse and rounded angle.
The whole skull thus appears bent downward in its anterior half.
On the anterior portion of the dorsal edge of thé orbit there are, in all my medium-sized specimens,
two backwardly directed spines, but in my two large specimens there is but one spine, a
Zoologies. Heft 67. j g