6 
PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Geo graphical distribution. Pacific coast region, from northern 
California to Alaska. 
General characters. Very large and dark colored. 
Color. Uniform dark sooty brown, becoming black on the tail; 
chin white. 
Size. Judging from the fur skins 1 have seen, the measurements 
of the type give but slight indication of the maximum size of this 
subspecies. 
The skull. Very large and heavy. The brain case large and 
deep, and very broad across the mastoids; differing essentially in 
these particulars from the skulls of any of the eastern mink. The 
interorbital region is well arched as in P. vulgivagus and the audita! 
bullae are quite deep. The dentition is heavier than in P. lutreo- 
cephalus , but not so heavy as in P. vulgivagus. 
Remarks. Putorius energurnenos is the dark-colored form of 
the Pacific coast and is the largest of all our mink. 
A young topotype, No. 3536, is of especial interest as showing in a 
more marked degree than the type the great size and breadth of the 
brain case. The color of this specimen is a nearly uniform black. 
PLATE 1. 
1. Putorius ( Lutreola ) vison lutreocephalus (Harlan). 
No. 1947, coll, of E. A. and 0. Bangs. $ adult from Liberty Hill, Conn. 
2. Putorius ( Lutreola ) vison vulgivagus Bangs. 
No. 2751 (the type), coll, of E. A. and O. Bangs. $ adult from Burbridge, 
La. 
3. Putorius ( Lutreola ) vison vulgivagus Bangs. 
No. 2751 (the type), coll, of E. A. and 0. Bangs. $ adult from Burbridge, 
La. 
PLATE 2. 
1. Putorius (Lutreola ) vison (Schreber). 
No. 2428, coll, of E. A. and O. Bangs. $ adult from Annapolis, N. IS. 
2. Putorius ( Lutreola ) vison lutreocephalus (Harlan). 
No. 1947, coll, of E. A. and O. Bangs. $ adult from Liberty Hill, Conn. 
3. Putorius ( Lutreola ) vison energurnenos Bangs. 
No. 3555 (the type), coll, of E. A. and O. Bangs. $ young adult from Sumas, 
B. C. 
