484 Bulletin A merican Museum of Natural History. [ Vol . X V I , 



the rostral portion of the skull being similiarly narrow and elongated in 

 comparison with the other species of Phoca. The type skull, which is ap- 

 parently that of a ' young adult ' male, measures as follows : Basal length, 

 205 mm.; greatest zygomatic breadth, 112; mastoid breadth, 117; front 

 border of premaxillae to pterygoid hamuli, 106; front border of upper 

 incisors to posterior border of upper molar, 61 ; front border of premaxillas 

 to meatus auditorius, 143 ; palatal length (along median line), 78; palato- 

 maxillary suture to pterygoid hamuli, 44; palato-maxillary suture to 

 anterior border of foramen magnum, 128; palatal width between the 

 molars, 39; length of upper toothrow, 43.5; length of nasals, 45; breadth 

 of nasals at fronto-maxillary suture, 1 1 ; least interorbital breadth, 1 1 ; 

 length of brain-case, 85; greatest width of brain-case, 93; length of 

 lower jaw, 128; lower toothrow, 43. An adult skull, apparently female, 

 is smaller, the principal dimensions being as follows: Basal length, 182; 

 zygomatic breadth, 102; mastoid breadth, 106; front border of premax- 

 illae to pterygoid hamuli, 94; front border of premaxillse to meatus audi- 

 torius, 128; palatal length (along median line), 70; palato-maxillary su- 

 ture to foramen magnum, 115; palatal width between molars, 35; length 

 of upper toothrow, 40; length of nasals, 37; width of nasals at fronto- 

 maxillary suture, 9; length of lower jaw, 112; lower toothrow, 38.5. 



This form ranges from the southeastern coast of Kam- 

 schatka north to Point Barrow, Alaska, and is represented by 

 the following specimens, which are skulls only: Avatcha Bay, 

 Kams., Nos. 83447 and 83448, U. S. Nat. Mus., apparently 

 male and female, both adult but not old, collected by Dr. 

 Stejneger in 1896; Plover Bay, Siberian side of Bering Strait, 

 No. 6783, U. S. Nat. Mus. (formerly; now No. 6970, Mus. 

 Comp. Zoology), collected by Col. Buckley; Point Barrow, 

 Alaska, No. 16761, U. S. Nat. Mus., apparently ?, collected 

 by John Murdoch. Also three skulls, all collected by the E. A. 

 Mcllhenny Expedition (orig. Nos. 22 and 30, Acad. Nat. Sci., 

 Philadelphia, and No. 5 3 90, Wistar Institute, Philadelphia), and 

 all labelled as female by the collector. Detailed measure- 

 ments are given of all these skulls in the table on p. 497. 



Phoca ochotensis macrodens differs from P. ochotensis, so far 

 as the skulls are concerned, in the much greater size of the 

 teeth, which, while the toothrow is of the same length in both, 

 are much larger and stand closer together, leaving much smal- 

 ler diastema between those of the upper jaw, while in the 

 lower jaw they are in close contact, and sometimes crowded, 

 so that pm 2 is generally, and pm 3 is sometimes inserted 



