430. CONTRIBUTIONS TO A REVISION OF THE 
Type Locality.—Vake Kichelos, Kittitass county, Washington ; altitude about 8000 
feet. Type No. 616, yg. ad. 3, in the collection of 8. N. Rhoads; collected in fall or 
winter® of 1892—93, by Allan Rupert. 
Geographic Distribution.—Pacitic slope of North America, from Alaska to Cali- 
fornia. 
Color.—Of type: Lighter than hudsonica, with a browner cast, approaching nearly 
to lataaina. Average of coast specimens from Puget Sound northward, ruddy seal 
brown, sometimes very dark in Alaskan coast specimens. Lower parts from breast to 
end of tail much lighter (Mars-brown) than back. Ventral region conspicuously lighter. 
Lower head, neck and breast very pale wood brown, almost dirty gray. 
Anatomical Characters.—Size, very large.t Tail normal. Inferior webs of feet 
and palmar interspaces nearly naked. Hind foot not recorded in type, the caleaneum 
missing ; no measurements of other specimens available. Skull largest of the North 
American otters (reaching a maximum of 119 mm. in occipito-nasal length and 83 mm. 
in zygomatic expanse in an Alaskan coast example) ; teeth relatively weak, less crowded 
longitudinally than in hudsonica. Interorbital width relatively very great, nearly 13 
times postorbital constriction ; postorbital processes long and stout. Mastoid and zygo- 
matic proportions as in hudsomca. Audital bulle remarkably flattened. 
Measuwrements.—See tables. 
Remarks.—The type specimen, though taken in the mountains and not fully mature, 
is large and has a skull which would have, perhaps, eventually equaled the maximum 
size recorded above for an Alaskan specimen of much greater age. A very old female 
skull from the vicinity of Puget Sound confirms fully the diagnostic characters of 
pacifica as given. 
In treating of the otters of the Pacific slope of America we are confronted with 
two nominal species to which they have been doubtfully referred by authors. In point 
of time the first to be considered is the Viverra aterrima of Pallas,{ described from a 
hunter’s skin, lacking skull and feet, taken in northeast Siberia, “ between the Uth 
and Amur riyers.” Schrenck and Middendorff listed this animal in their works on 
Siberian Zodlogy with the remark that they were unable to verify its existence or clear 
up the mystery of its strange characters as given by Pallas. Mr. Thomas (P. Z S., 
l. c., p. 199) queries, on the basis of a mistaken suggestion of Dr. Coues, whether it may 
* The season of capture was not recorded, but the pelt indicates that it was taken in full winter fur. 
{Ihave no measurements of Alaskan otters, but judging by the great size of the skulls from there they. must 
greatly exceed any known species of Lutra. On the basis of the skull they must attain a maximum length of over 1400 
millimeters. 
t Zoog. Rosso. Asiat., I. ¢. 
