170 ODOBJENUS OBESUS PACIFIC WALRUS. 



within thirty degrees of the western limit of the range of the 

 Pacific animal. In view of these facts, the question arises as 

 to whether the Atlantic species may not occasionally pass along 

 the northern coast of Asia so far as to sometimes reach the 

 habitat of the Pacific species. 



NOMENCLATURE. The first specific name applied to the Pa- 

 cific Walrus is obesus, given by Illiger in 1815, in his " Ueber- 

 blick der Saugethiere uach ihrer Vertheilung iiber die Welt- 

 theile."* In this paper this name is three times used as a dis- 

 tinctive appellation for the Pacific Walrus, namely, (1) in his 

 list of the species of Northern Asia, in which " Tricliecltus ros- 

 marus" and " Trichechus obesus" are both given; (2) in his list 

 of the species of North America ; and (3) in his remarks respect- 

 ing the first-named list. In these remarks (1. c., p. 75) he says, 

 "Die beiden Arten des Waitresses, TrichecJtus obesus \uu\ [T.] 

 Rosmarus, siud schon bei Nord-Asien vorgekommen." For Eu- 

 rope he gives only T. rosmarus (1. c., p. 50), respecting the dis- 

 tribution of which he says, " Der Trichechus Rosmarus, das Wall- 

 ross, lebt an den eisigen Kiisten von Nord-Europa, Nord-Asien, 

 und des ostlichen Nord- America " (1. c., p. Gl). It is thus not 

 quite clear whether he considered his T. rosmarus to have a 

 complete circuinpolar range, with T. obesus as a second species 

 occurring only on the northeastern shores of Asia and the north- 

 western shores of North America, or whether, as is more probable,, 

 he merely meant that T. rosmarus ranged eastward along the Arc- 

 tic coast of the Old World to the northern shore of Western Asia 

 (as is the fact), and was replaced on the Pacific shores of Asia and 

 America by T. obesus. In either case he recognized as a distinct 

 species, under the name T. obesus, the Walrus of the North Pa- 

 cific and adjacent portions of the Arctic Ocean. In the same 

 paper is also a reference to a Trichechus " divergensf respecting 

 which he thus observes : "Auser deni schou bei Europa erwiihn- 

 ten Wallross, Trichechus Itosmarus, fiudet sich an der westlichen 

 Nord-Amerkamschen und uahen Ost-Asiatischen Kiiste, und 

 dem Eise dieser Meere, vielleicht aber auch an der ganzen Kiiste 

 des Eismeers das von Cook beschriebene und abgebildete Wall- 

 ross, das ich wegen mehrerer Verschicdenheiteu, besonders der 

 Hauziihne, als eigue Art miter dein Namen divcryens aufge- 

 fiihrt habe " (1. c., p. 08). He thus, in the same paper, appears to 

 recognize two species of Pacific Walruses. The name divcryens^ 



*AbhaiuI. der Akad. der Wissensch. xu Berlin, 1804-1811, (1815), pp. o-l, 

 70. 75. 



