that connect the Orders and Families of Birds. 501 
species, the M. albellus, Linn., which is intermediate in its 
breadth and depression, it preserves its connexion with the 
Anates. We hence pass to the fifth and last group of the family, 
which, with the bill of the Anates, retains most of the characters 
conspicuous in Mergus. ‘The forms most prominent in it, repre- 
sented by the different Linnean species A. ferina, clangula, his- 
trionica, and mollissima, possess a strongly lobated hind toe* ; 
they frequent the ocean for the most part, where they dive with 
the greatest facility and for a length of time; and they live 
chiefly on marine animals. "Their legs are also thrown behind 
the equilibrium of their body ; and thus also they evince their 
contiguity to the typical Natatores. By means of the group 
which contains A. mollissima, our well-known Eider Duck and 
its congeners, where the bill, with an elevated protuberance at 
the base, approaches that of the Anas olor, Linn., we find our- 
selves brought round to the Cygnus of the present day, which 
forms part of the first division. ‘That genus in like manner de- 
viates partially from the conterminous genus Anser, in its legs 
being thrown more backward, and its consequently greater awk- 
wardness in walking. Here then the affinities are evident which 
thus establish the perfect return of the series of the Anatide into 
itself. Before we leave the family, I must indulge myself in 
observing a most conspicuous peculiarity which marks the series 
of affinities among these groups. "The long and slender neck | 
observable in the Grallatores is preserved in such groups of the 
Anatide as are most conterminous to that order, such as Cygnus, 
2.5 Ceux qui ont au pouce un large rudiment làche, plongent habituellement 
et long-tems : ces derniers vivent sur les grandes mers." Temm. Man. p. 831.—* Les 
espèces dont le pouce est bordé d’une membrane, ont la tête plus grosse, le cou 
plus court, les pieds plus en arrière, les ailes plus petites, les doigts plus longs, les 
palmures plus entières. Elles marchent plus mal, vivent plus exclusivement de pois- : 
sons et d'insectes, et plongent plus souvent.” Cuv. Regne Anim. i. p. 532. 
3T2 Anser, 
