NATATORES. 255 



other orders and their subdivisions, may be traced in the pre- 

 sent one ; and its connexion with them, at various points, 

 satisfactorily established by the tendency of particular ge- 

 nera and species. It is also through the connexion of this 

 order with that of the Raptores (however improbable it may 

 at first view appear), that the circle of the orders themselves 

 is completed. This seems, however, to be effected by the in- 

 tervention of a peculiar form in the family of the Pele- 

 canidce ; I allude to the genus TacJiypetes of VIEILLOT (the 

 type of which is the Pelecanus Aquilus of LINN^US), of 

 which the species, both in form, flight, and predatory ha- 

 bits, shew a marked and near approach to the true raptorial 

 birds. As the affinities of each family will be more particu- 

 larly alluded to under their respective heads, I pass without 

 further preface to that of the Anatidce, with which the order 

 commences. 



FAMILY I. ANATID^E. 



THE Family of Anatidce, to which we are introduced by 

 the connexion subsisting between certain of its members and 

 others of the preceding orders, forms the first aberrant fa- 

 mily of the Natatores, and is formed of the extensive Lin- 

 nean genus Anas with that of Mergus. The first it has 

 been found necessary, by subsequent systematists (from the 

 difficult task of reconciling and adapting the Linnean gene- 

 ric characters to the vast variety of species it contains), to 

 separate, either by sectional division, as adopted by M, 

 TEMMINCK, in his " Manuel d'Ornithologie" (which division 

 is in fact equivalent to the subfamilies of the present sys- 

 tem), or by the institution of distinct genera, the plan of 

 ILLIGER, as well as other naturalists of the present day, and 

 in which they do but follow the older ornithologists who pre- 

 ceded the learned Swede. In conjunction, however, with the 

 genus Mergus, it appears clearly to admit of being separated 



