36 pnociD.-E. 



largest grinders. The canine tooth is displaced, being thrust out- 

 wards beyond the line of the other teeth. There are five grinders 

 with single roots, the fifth very small. In the lower jaw there are 

 five grinders. In the adult the incisors are obliterated, except the 

 lateral pair of the upper jaw. The fifth grinder also disappears, and 

 sometimes the fourth. — j\Iacr/ilUv. N((t. Lib. vii. 



In the very young the cutting-teeth &, all, especially the two upper 

 lateral, deciduous ; canmcs ^, upper elongate, lower conical like the 

 grinders ; grinders ^, small, rather compressed. — Eapp, Bull. Sci. 

 Nat. xvii. 280. 



The young Walrus has three teeth in each premaxillary bone, and 

 • two on each side of the fore part of the mancUble. They soon dis- 

 appear, except the outer pair of the upper incisors, which remain 

 close to the maxillo-premaxillary sutiu-e on the inner side of the long 

 canine tusks, and, by their thick obtuse form, seem to commence a 

 series of small and simple molars. In the adult there are usually 

 three molars on each side behind the permanent molariform incisor, 

 and there are four similar teeth on each side of the lower jaw. — Owen, 

 Cat. Osteal. Series Miis. Coll. Surgeons, p. 630. no. 3860. 



The skeleton is described by Prof. Owen, op. cit. p. 630. nos. 3860 

 to 3919. 



^ 5 I Odobenus, Brisson, Regne. Anim. 48. 



Eosmarus, Scopoli, Introd. H. N. 1777. 

 Tricbechus, Linn. Si/st. Nat. i. ; Nilsson, Vet. Akacl Handl. 1837 ; 



Skand. Fauna, t. ; Wierpn. Arch. vii. 322 ; Fleming, Phil. Zool. 



ii. 187 ; Hupp, Bull. Sci. Nat. xvii. 280 ; Fischer, Si/n. 678 ; F. Cuv. 



Diet. Sci. Nut. lix. 465, 1829 ; Gray, Cat. Seals B. M. 30. 

 (Tribe) Trichecina, Turner, Proc. Zool. Sue. 1848, 88. 

 :Morse, F. Cuvier, Dents rles Mamm. 233. t. 95, 1825. 

 TrichechiJas seu Campodontia, J. Brookes, Mus. Catal. 37, 1828. 



M. F. Cuvier thinks the Morse forms an isolated family, distin- 

 guished by the great breadth of its muzzle, the length of its upper 

 canines, and the form of its teeth. It has the same organs of move- 

 ment and intestinal canal as the Seals. — I). S. N. lix. 465. 



Professor Bacr illustrates his paper with a map showing the geo- 

 graphical distribution of the "Wakus in the Ai'ctic Sea. 



For the chase and uses of the Morse, see Wrangel, ' Nordkiiste von 

 Sibirien,' ii. 319, 320. 



1. Trichechus Eosmarus. Morse. . 

 Pale brown ; when young black, when old nearly white. 



Trichechus Piosmarus, Linn. S. N. i. 39 ; Midler, Prod. Zool. Dan. i. ; 



Schreher, Siiuyeth. 262. t. 79; Nilsson, Wiegm. Arch.xii. 322; Blainv. 



Osteog. Phoca, t. 1 & 4 ; Fischer, St/n.' 243 ; Baer, 3Iem. Acad. 



Petersh. iv. 97. t. 4, 1838; Mem. Mus. vii. t. 9; Gray, Cat. Seals 



B. M. 32 ; Owen, Proc. Zool. Soc. 1853 ; Ann. ^- Mag. Nat. Hist. 



1855, XV. 226; Cat. Osteol. Coll. Mus. Coll. Surg. 631. 

 Eosmarus arcticus, Pallas, Zool. Rosso-Asiat. i. 269 ; Schrenek,Amur- 



Lande, i. 179; Volkmann, Anat. Anim. Tab. 1831, t. lO. I. 3 (skull). 



