GENERAL OBSEEVATIONS. 9 



"VValrus, and tlie Manatee, the. two last named constituting his 

 " lieiius Odohenus.'' Tliis was a marked retrocession from even 

 the system of Ivlein,* of a few years' earlier date, who brought 

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

 Manatee. Linne, in 17GG,t not only removed the Walrus from 

 the genus Phoca, in which he had previously placed it, to Tri- 

 chedt us, hnt also transferred it from his order JPera' to Bruta, 

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

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

 Tiichechu-s, as at this time constituted, was equivalent to Bris- 

 son's genus '^ Odohenus.'''' 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 Trichechm contained also the Dugong and the 

 Manatee. Gmelin,|| in 1788,folloM-ed the Linuieau arrangement 

 of 17G6; the Wah-us, as usual from the time of Brisson to 

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

 ally with the Sirenians. Blumenbacli,tl from 1788 till as late 

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

 the genus Trichechns. In other respects, the Walrus appears 

 with new associates, tlu^ genus Trichechus being united with 

 Ornlthorliynchux to form a "iaiidly"(!) of his "order" Pahnata. 

 The order PaJnuifa, as the name imphes, Avas composed of the 

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

 "A. Glires'^ (consisting of the genus Castor); '^B. Fercc''^ {Phoca 

 and. Lutra); and ^^C. Bruta'''' {Ornithorhynchus and Trichechns). 

 This is essentially also the arrangement proposed by Klein in 

 1751. 



The first stei) toward dismembering the unnatural conglo- 

 meration known previously under the names Trichechus and 

 Odohenus was made by Eetzius** in 1791, who divided the 

 genus Trichechus of former authors into three genera, namely, 

 Ifanatus, for the Manatee; RydromaUs, for Steller's Sea-Cow 

 {= Rhytina Ilhger, 1811) ; and Trichechus, the last embrac- 



**Quacl. Disp. Brev. Hist. Nat., 17.^1, pp. 40, 92. 



t Syst, Nat., ed. 12, 1706, p. 49. 



t Syst. Reg. Aiiim., 1777, p. 593. 



? Siiugetli., ii, [1776?], p. 260. 



II Syst. Nat.,i, 59. 



UHaudb. d. Naturgcsch., 1788, p. 142, aud later editions. 



^*Kongl. Yeteiisk. Acad, uya Haudliiig., xv, 1794, pi>. 286-300. 



