THE NORTHERN RIBBON-FISH. i) 
end of the quadrate. From a conspicuous prominence on the inner surface, near 
the proximal end, a slender Mrckenr’s cartilage is continued forward as far as the 
anterior extremity of the bone. 
The dentary is also triangular, the posterior edge presenting a wide indentation 
to receive the anterior portion of the articular. The anterior extremity of the 
dentary is much thickened, and in the fibrous tissue forming the mandibular 
symphysis two small separate ossified nodules were found. The upper border of the 
dentary bears four or five small teeth anteriorly. 
The angular is a small triangular flat bone, which lies on the inner face of the 
articular at its lower angle. 
Each pre-maxilla is composed of a vertical portion which bounds the gape, it 
becomes horizontal above, to approach its fellow in the middle line, and is thence 
continued backwards as a long pointed “nasal” process. The latter is rounded and 
smooth externally, but its mmer face is flat and applied to that of its neighbour. 
Anterior to the middle of this process, on the under side of the bone, is a slight 
projection directed downwards, which articulates with the internal process of the 
maxilla. Below, the processes are attached strongly to a median cartilage, which is 
large posteriorly, and is continued backwards beyond the processes a little distance. 
At the posterior end of the projection just mentioned, it suddenly is reduced to a 
thin median strip, which extends forwards to a point rather more than half-an-inch 
from the anterior end of the pre-maxilla. This cartilage is found in other Teleosteans, 
e.g., the Cod (c.f, PARKER), but is here greatly developed to form a smooth surface ° 
which slides over the tegmen cranw. The smooth outer surface of the process is 
continued on to the vertical process or body as a ridge separating two shallow 
grooved fossx. The posterior one receives the anterior edge of the maxilla. The 
anterior is sub-cutaneous (Pl. I., Mig. 1). Near the anterior end, and near the 
middle line are a series of small teeth, four or five in number. 
Fig. 4. 
p.-mz., pre-maxilla ; mx., maxilla ; ¢., cartilage. 
The mawille are situated external to and under the pre-maxille. Each consists 
of a flat sculptured sub-cutaneous plate, of an irregularly oval shape, and an 
inwardly-directed process, meeting its fellow below the pre-maxilla, and sending 
B 
