GENERAL OBSERVATIONS. 



AValrus, and the Manatee, the two last named constituting his 

 genus Odobcitus." This was a marked retrocession tVom even 

 i IK- system of Klein,* of a few years' 1 earlier date, who brought 

 together as one family the Seals, Otters, Beaver, AYalrus, and 

 Manatee. Linne, in 17GO,t not only removed the AYalrus from 

 the genus Phoca, in which he had previously placed it, to 2V/- 

 chechus, but also transferred it from liis order Fern* to Brnta, 

 which thus contained not only the AValrns, but such a diverse 

 assemblage as Elephants, Sloths, and Anteaters. Linne's genus 

 Tricht.rhnn, as at this time constituted, was equivalent to Bris- 

 son's genus Odobcnux." Erxleben,| who recognized no higher 

 groups than genera, placed the Walruses and Seals together im- 

 mediately after the Carnivores. Schreber, at about the same 

 date (1777), adopted a similar classification, the Walrus stand- 

 ing next after the Elephant and preceding the Seals. Schre- 

 ber's genus Trichirliitx contained also the Dugoug and the 

 Manatee. Gmelin,|| in 17<S8, followed the Linua?an arrangement 

 of 1760; the AYalrus, as usual from the time of Brisson to 

 Gmeliu, standing next to the Elephant, and associated generic- 

 ally with the Sireniaus. Blumenbach,^] from. 1788 till as late 

 even as 1825, still arranged the Walrus and the Sirenians in 

 the genus TricJicchiix. In other respects, the AValrus appears 

 with new associates, the genus Trlcheclius being united with 

 Ornithorhynclius to form a family" (!) of his ''order" Plita. 

 The order Palmata, as the name implies, was composed of the 

 web-footed mammals, and divided into three "families," namely, 

 "A. Glires'- (consisting of the genus Castor)', U B. Fera?" (Plioca 

 andiMfm); and >k C'. Bruta" (Ornifhortyynchus and Triclieclius). 

 This is essentially also the arrangement proposed by Klein in 

 1751. 



The first step toward dismembering the unnatural conglo- 

 meration known previously under the names TricJiechus and 

 Odobenuft was made by Eetzius** in 1794:, w r ho divided the 

 genus TrichechH* of former authors into three genera, namely, 

 Ulanatus, for the Manatee; Hydromalis, for Steller's Sea-Cow 

 (= Rhytina Illiger, 1811) 5 and Triclieclius^ the last embrac- 



1. Disp. Brev. Hist. Nat., 1751, pp. 40, 02. 

 tSyst. Nat., ed. 12, 17G6, p. 40. 

 t Syst. Reg. Anim., 1777, p. 50::. 

 Saugeth., ii, [1776?]- P- 2! Id. 

 || Syst. Nnt. : i, 50. 



HHaiidb. d. Naturgesch., 17S, p. 14','. and later editions. 

 * Koiigl. Vetensk. Aead. iiya Handling., xv, 1704, pp. 28I1-300. 



