DR. J. MURIE ON THE ANATOMY OF THE SEA-LION. 503 
scooped; the jugal extension is a tapering rod. The jugal bone is not very stout, 
though at its middle high, in an upward angle. Bifurcate in front, it forms a firm 
union with the maxillary retrovert process. 
A considerable part of the face or muzzle is taken up by the intermaxillary, so that, 
excepting the canine eminence, each maxillary chiefly outflanks the cheeks only. The 
basal segment of the maxilla rises high, is flatly convex, and of fair breadth. Behind, 
the canine eminence is deeply and widely grooved, where lie the thick infraorbital 
nerves and vessels. ‘There is a small but distinct antorbital prominence. The max- 
illary orbital surface is moderate, and tolerably vertically concave forwards. The pala- 
tine region of the maxillary is of fair breadth, and terminates in a long spear-shaped 
palatine strip guarding the palatine plates of the palate-bones almost to the posterior 
nares. Each premaxilla is flattish and truncate anteriorly towards the alveolus, and 
rises therefrom in a narrowing outspread arch enclosing the anterior nares. The narial 
orifice in front is heart-shaped, 13 inch deep and 14 inch at its upper widest part. The 
upward strip of the premaxilla is inserted between the nasal and maxillary bone as a 
narrow wedge. The large turbinals are much convoluted and almost occlude the narial 
passages, but within the maxillary area. The vomer is in great part hidden, and has 
no connexion with the horizontal palatine plates. 
The nasals in some respects are like the premaxillaries in being wide below and 
narrow above. Each is 1:8inch long, and about half an inch at widest or below. They 
are suturally connected nearly their whole length, posteriorly divaricating; the forks 
fit into the frontal. One half of their outer margin abuts against the maxilla, the 
remainder in front lies upon the premaxilla. 
The frontal bones are peculiar from their length, postorbital processes, and great 
constriction behind these. Their upper surface is smooth and flat anteriorly, and widely 
convexly arched behind. Their orbital surfaces are of great length, considerably scooped 
out, and but moderately deep, a long vacuity existing between them and the maxillo- 
palatines. 
The palatine plates of the palate-bones, as has been noticed by many authors, are un- 
commonly long and broad—in this case fully 24 inches in antero-posterior, and above 
12 inch in transverse diameter. Their hinder margins are transversely abrupt, and the 
posterior nares constricted. Laterally and exteriorly the palatine walls reach high, and 
present a great pterygo-sphenoidal surface. 
The basisphenoid is short, but wide. The pterygoid processes stout, and with a sharp 
recurved hamular process. ‘The alisphenoids are fair-sized, distinguished by a square 
boss where they join the postfrontals. ‘There seems, however, to be a large orbital 
plate: but this is mainly composed of the postfrontal; for the orbito-sphenoidal area 
is very narrow and small. 
ce. The Mandible.—The two halves of the inferior maxilla have no bony anchylosis, but 
are united to each other by synchondrosis. This separation is not merely the result of 
4a2 
