326 NORTH AMERICAN MUSTELID^. 



Generic characters.— Z)e«/aZ formula: i. |^ ; c, ^^; pm. |^ ; 

 m. l~l=^ J g =32.* Grinding teeth very peculiar in shape, without trench- 

 ant edges or acute angles, all being bluntly tuberculous on the crown, and 

 rounded off in contour. Molar of upper jaw irregularly oval. Last upper 

 premolar not dissimilar in shape, and but little smaller ; others abruptly 

 less in size. Anterior under molar much the largest of the lower teeth ; 

 posterior premolar and posterior molar next in size. Skull generally as in 

 Lutrinod, in straight upper outline, very short rostrum, truncate in front 

 and flat on top, backward production of palate, size and shape of ante- 

 orbital foramen, &c., but much broader for its length ; thus, the interptery- 

 goid emargination is, if anything, broader than deep. Sagittal and occipital 

 crests and mastoid processes very salient. Glenoid not locking condyle. 

 Coronoid of mandible sloping backward with convex fore and straight or 

 slightly concave posterior border, its bluntly rounded apex in the vertical 

 line over condyle. 



General external aspect of Lutrina', but limbs modified. Fore legs short, 

 •with small paws ; digits webbed ; palms naked. Hind feet with elongated 

 digits, flipper-like, webbed, and furry both sides; claws small, hidden in 

 the fur. Habits aquatic ; habitat marine. 



The character of the genus is so fully exhibited in the fol- 

 lowing account of the only species that further remark is not 

 required in this connection. 



The Sea Otter. 



• Enbydris lutris. 



Plates XIX, XX. 



Intra marina, StelUr, N. C. Petrop. ii. 1751, 367, pi. 2&.—Erxl. Syst. Anim. 1777, 445 (descrip- 

 tion pertinent, but synonymy mixed with that of another species).— (Sc/irei/. Saug. iii. 

 1778, 465, pi. 128 (Steller).— Zmm. Geog. Gesch. ii. 1780, 313, no. 211.— <S/iau', G'en. Zook 

 i. 1800, 444, pi. 101.— Z>t'sm. Mamm. i. 1820, 169, no. 291 ; " ISTouv. Diet, xviii, 216 ; Ency. 

 M^th. pi. 79, f. 2:'— Harlan, Fn. Amer. 1825, 12.—Gloger, N. Act. Nat. Cur. xiii. pt. ii. 

 1827, 510 (proposes Latax as a better name than Ptisa), 875 seq.; " Isis, ii. 1829, 132 seq.,- 

 r6rus8. Bull. XV. 136 ^ej."- Godw. Am. N. H. i. 1831, 228. pi. — , f. i.— Wagn. Arch. f. 

 Naturg. ii. 1836, 281. 



Sutra [sic] marina, H. W. Elliott, Amer. Sportsman, Sept. 12 and 19, 1874 (biography; 

 under pseudonym of "Alaska"). 



Intra (Enliydra) marina, Rich. F. B.-A. i. 1829, 59, no. 21 ; Z06I. Beechey's Voy. 1839, 5. 



Enliydra marina, Flem. Philos. Z06I. ii. 1822, IBl.—Oriff. An. Kingd. t. 1827, 132, no. 369.- 

 Martin, P. Z. S. iv. 1836, 59 (osteology).— A ud. d-Bach. Q. N. A. iii. 1853, 170, pi. 137.- 

 Newb. P. R. R. Rep. vi. 1857, 43.— JSd. M. N. A. 1857, 189.— Coop, dk Suck. N. H. "Wash. 

 Terr. 1860, 115.— Dall., Alaska and its Res. 1870, 489 (habits).- JT. W. Elliott, Condition 

 of Affairs in Alaska, Svo ed. chap. v. 1875, pp. 54-62 (history, habits, the chase, eco- 

 nomic and commercial relations). 



* It is said that the young Sea Otter has i. |^|,like all other MustelidiB. 

 The middle pair of incisors are those that are wanting in the adult. Prof. 

 .Baird (M. N. A. 1857, 189), overlooking the peculiarity of the incisor formula 

 of the adult, but correctly noting the one less premolar than in LiUrince, 

 gives a wrong total of 34 teeth in all, instead of 32. 



