10 THE VOYAGE OF H.M.S. CHALLENGER. 



which it will be seen that in the male the width is proportionally greater than the 

 height. In the male also the upper jaw is prolonged in front of the anterior nares, 

 both absolutely and relatively more than in the female, and the superior maxillae in the 

 male extend laterally beyond the prernaxillae, much more than in the female, which is 

 due partly to the much greater magnitude of the incisor and canine teeth in the male 

 sex, and partly to this region of the skull being associated with the development of a 

 proboscis in the male and not in the female. There is therefore a marked difference in 

 the two sexes between both the length and breadth of the pre-nasal part of the skull, and 

 between the adult and younger male crania in the same region. 



As the nasal cartilages had been preserved in the Kerguelen Island male skull I 

 examined their arrangement and connections. Attached to the anterior border of the 

 two nasal bones was a triangular cartilaginous plate, 80 mm. long, the apex of which was 

 directed forwards. It prolonged the roof of the nose forwards in the plane of the nasal 

 bones, and had at one time evidently been divided into two lateral halves, as traces of a 

 median suture could be seen on its upper surface. By its under surface it was fused with 

 the septal cartilage, which was prolonged forwards in the mesial plane from the anterior 

 border of the mes-ethmoid for 12 mm. in front of the premaxillaries. Where it rested 

 in the vomer and on the prernaxillae it was broadened out into a base varying in width 

 from 30 to 40 mm. Attached to each lateral border of the roof cartilage of the nose was 

 a lateral cartilage, which passed outwards as far as the superior maxilla, where it formed 

 the side wall of the anterior nares. The two formed a pair of alar cartilages, and were 

 near their maxillary attachment fibrous in their structure. 



The antorbital (maxillary) process was a well-marked triangle in both sexes, and 

 was situated immediately behind the anterior nares, whilst the infraorbital foramen was 

 somewhat in front of the nasal opening in the skull. The postorbitals were wanting, 

 but in one skull a stroug fibrous band stretched from the orbital process of the zygomatic 

 arch to the side of the frontal bone, and completed the ring of the orbit posteriorly. 

 The ascending processes of the superior maxillae, like the nasals, were received between 

 the two diverging frontals. 



The hard palate was widest immediately behind the last molar tooth ; it was concave 

 anteriorly and mesially, though without much depth, and its outer edge behind the 

 dentary arcade was scarcely raised above the general plane of the surface. In one male 

 skull this edge extended 132 mm. from the socket of the 5th post-canine to the palato- 

 pterygoid suture, and in the largest female 69 mm. The palatal surfaces of the 

 prernaxillae were triangular, and the apex of each was received between the superior 

 maxillae ; an almost obliterated naso-palatine foramen was situated mesially between the 

 prernaxillae. The palato-maxillary suture was almost transverse, and placed some 

 distance behind the last molar tooth, though immediately behind the root of the malar 

 process of the superior maxilla ; behind it the palate diminished considerably in breadth, 



