1885.] DR. ST. G. MIVART ON THE PINNIPF.DIA. 491 



the pterygoid, palatine, presphenoid, and basisphenoid. There is a 

 large paroccipital process and a considerable mastoid process. The 

 meatus auditorius externus is prolonged well outwards, its lip is 

 completed in front. The considerable palatine foramina are placed at 

 about the antero-posterior middle of the j.alate. There is no angular 

 process of the mandible near the condyle, hut only a single process, 

 which seems to correspond with the subangular process of those 

 Seals which have both these processes. The coronoid process rises 

 well above the mandibular condyle. 

 Dentition :— I. ;, C. \, P. ^, M. }=32. 



The molars are two-rooted except the first, which, with the last, is 

 smaller than the others. The incisors are notched transversely on 

 the inner side of the crown. The canines are large. The molars 

 have strong conical crowns with only slightly developed accessory 

 cusps from a strong cingulum, the inner part of which is well 

 developed. 



All foregoing genera Monachus, Ommatophoca, Leptonyx, and 

 Stenorhjnchus agree together and differ from the genera Phoca and 

 HalicJicerus in having only four upper incisors ; nails of pes rudi- 

 mentary or absent, and the first and fifth digits of that extremity 

 greatly exceeding the others in length. The six genera then may 

 be arranged in two groups thus respectively characterized and named 

 Phocina und Stenorhynchince, as has been done by Professor Flower '. 

 Cystophora- . — This genus of one species, of the North Atlantic 

 and Arctic seas, is characterized by having the dorsal facial skin of the 

 male capable of distension by the inflation of a sac which underlies 

 it and is connected with the nostrils. The distended skin thus 

 forms a sort of hood covering the dorsal part of the head. As in 

 the Stenorhynchince, the first and fifth toes exceed the others. They 

 also have prolonged cutaneous lobes. The nails are tolerably deve- 

 loped in all the extremities. There are 15 dorsal, 5 lumbar, 3 sacral, 

 and 14 caudal vertebrae. 



In the skull the premaxillse do not rise to the nasals. The latter 

 are small and not ancliylosed together. The orbits are very large. 

 The anterior nares are' very wide, especially towards their upper 

 part. The maxilla develops a small preorbital process. There is a 

 large crista galli, but a small cerebellar fossa to the petrosal. There 

 is a moderate-sized suborbital foramen, and there may be a deep 

 fossa beneath or external to it, as is sometimes the case in P. grcen- 

 landica. I have observed no defects of ossification between the 

 jiterygoid, palatine, and adjacent bones. If there are any defects of 



' See Ins paper on the Maujmalia in the Eucyc. Biit. vol. sv. p. 443. 



2 Phoca cristata, Erdeben, Syst. ]S'at. p. otJO ; i'abric. Skrivt. af Xaturh. 



Selsk. i. 2, p. 120, tab. 12. fig. 2 ; Desm. Mam. p. 241 ; Harlan, Fauna 



N. Y. p. 106. 

 PJioca mifrata. Cuvier. Oss. Foss., Atlas, ii. pi. 219. fig. 3. 

 Cy&fophora crisUiici, Nilsson, Vet. Akad. Handl. 1837 ; Gray, Voy. Erebus 



and Terror, Mamiii. p. 4, Cat. Seals Brit. Mus. (186(i) p. 40 ; Schreber, 



Fortgeselzt Waguer, vii. p. 48 ; Allen, N. Arner. Pinnipeds, pp. 462, 465, 



724. 

 Phoque a Capuchon, Buffon, Hist. Nat. Supp. vi. p. 324. 



