430 CONTRIBUTIONS TO A REVISION OF THE 



Type Locality. — Lake Kicbelos, Kittitass county, Washington ; altitude about 8000 

 feet. Type No. 616, yg. ad. tf, in the collection of S. N. Ehoads ; collected in fall or 

 winter* of 1892-'93, by Allan Rupert. 



Geographic Distribution. — Pacific slope of North America, from Alaska to Cali- 

 fornia. 



Color. — Of type : Lighter than hudsonica, with a browner cast, approaching nearly 

 to lataxina. 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. f Tail normal. Inferior webs of feet 

 and palmar interspaces nearly naked. Hind foot not recorded in type, the calcaneum 

 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 li 

 times postorbital constriction ; postorbital processes long and stout. Mastoid and zj^go- 

 matic proportions as in hudsonica. Audital bullae remarkably flattened. 



Measurements. — 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 sj>ecimen 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 rivers." Schrenck and Middendorff listed this animal in their works on 

 Siberian Zoology 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., 

 I. 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 foil winter fur. 



1 1 have no measurements of Alaskan otters, but judging by the great size of the skalls 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. c. 



