170 ODQBJ3NUS OBESUS PACIFIC WALEUS. 



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 nach 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 " Triclieclius ros- 

 marus" and " Triclieclius 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 Wallrosses, Trichechus obesm und [T.] 

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

 rope he gives only T. rosmarus (1. c., p. 56), 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 n (1. c., p. 61). It is thus not 

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

 complete circumpolar 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 meantthat 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 Triclieclius " diver gens? respecting 

 which he thus observes : "Auser dern schon bei Europa erwahn- 

 ten Wallross, Triclieclius Rosmarus, findet sich an der westlichen 

 Nord-Amerkanischen und nahen Ost-Asiatischen Kiiste, und 

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

 des Eisrneers das von Cook beschriebene und abgebildete Wall- 

 ross, das ich wegen mehrerer Verschiedenheiten, besonders der 

 Hauzahue, als eigne Art unter dem Namen divcrgens aufge- 

 fiihrt habe n (1. c., p. 68). He thus, in the same paper, appears to 

 recognize two species of Pacific Walruses. The name divergens, 



*Abhaii(l. tier Akail. der Wissenscli. /u Berlin, 1804-1811, (1815), pp. G4 r 

 70, 75. 



