1885.] DR. ST. G. MIVART ON THE PINNIPEDIA. 487 



process, bebiad which the bone is rouiided. The stylomastoid fora- 

 men lies in a deep groove which divides the mastoid from the bulla. 

 The meatus auditorius externus is produced outwards, but its lower 

 lip inclines so much upwards posteriorly that the aperture is made 

 to look more forwards than upwards, and the outer end of the lip 

 may be produced a little forwards in front of the aperture. There 

 is a postglenoid foramen. The posterior palatine foramina are 

 situated behind the middle of the palate. The pterygoid has a 

 distinct hamular process. The basis cranii has a surface bent convex 

 downwards between the occipital foramen and the presphenoid. 

 Venous canals traverse the inside of the exoccipitals and open on the 

 inner side of either occipital condyle. The mandible has a distinct 

 subangular process, and the angle is pressed up very near the con- 

 dyle. The symphysis may be long or short. 



Dentition : — I. 2, C. \, P. j, M. x=34. 



Molars, except the lirst, with two roots. Each upper molar has a 

 principal cusp with one or two accessory cusps behiud, and some- 

 times one in front of it. The lower molars have each a principal 

 cusp with one, sometimes two, accessory cusps in front of it, aud 

 generally two behind it. 



In P. vitulina the hinder margin of the palate is V-shaped, the 

 apex being forwards. The suture between the palatines and maxillie 

 forms a straight transverse line. The teeth are rather large and 

 multicuspidate. 



In P. (jranlandica the palate has a straight, transverse, hinder 

 margin. There is sometimes a distinct pterygoid fossa. The par- 

 occipital process may form a marked, nipple-like projection. The 

 teeth are more simple than in P. vitulina. 



In P. barbata the maxilla has a swollen outer surface ; venous 

 canals open inside the upper margin of the foramen magnum, and a 

 curious ridge runs downwards and forwards across the squamosal and 

 parallel witii the hinder root of the zygoma. The meatus auditorius 

 externus looks mainly upwards. Tlie paroccipital process is rather 

 prominent. The palate extends far back, and has an evenly concave 

 hinder margin. The two parietals form a small wedge-shaped pro- 

 cess which advances between the hinder margins of the two frontals. 



Halichcerus^. — This genus contains but one species, H. gryphus, 

 which inhabits the coasts of Scandinavia and the British Isles. Its 

 palms and soles are hairy, and it has five well-developed claws on 

 each foot, those of the mauus being the broader and more curved. 

 There are 15 dorsal, 5 lumbar, 4 sacral, and about 14 caudal 

 vertebrae. 



In the skull the same characters are found as those already attributed 

 to Phoca, except that there is a more decided defect of ossification 

 between the ali- and basisphenoids and the pterygoid, iloreover 

 the palatine foramina are much behind the middle of the palate. 



1 Fabric. Skrivt. af Naturb. Selsk. i. p. 167, tab. 13. fig. 4 ; Nilsson, Vet. 

 Akacl. Haudl. p. 377, tab. 34. figs. 1 & 2 ; Bell, Brit. Quad. p. 278 ; Gray, Cat. 

 Brit. Mus. p. 33 ; Schreb«r, Fortgesetzt Wagner, yii. p. 12 ; De Blain villa, 

 Osteogr. Phoca ; Allen, North Amer. Piun. p. 682. 



32* 



