490 Mr. N. A. Vigors on the Natural Affinities 



M. Cuvier has noticed* the union that takes place between 

 the last groups and those of the Ardeidce by means of the genera 

 Aramus, Vieill., and Eitrypyga, 111. These lead to the extensive 

 assemblage of species contained under Ardea, Linn., and Cico- 

 nia, Briss., both of which groups are connected by their general 

 form and habits, but differ by some minute yet strongly-marked 

 generic distinctions. Intermediate between Ardea and Ciconia 

 appear those forms which display so remarkable a dilatation of 

 bill, the Cancroma, Phcenicopterus, and Plotalea of Linnaeus. 

 The two last of these groups are equally distinguished by a 

 greater developement of the membrane that connects the toes, 

 than is observable in the other Waders which join them on each 

 side ; and in one of them, the Phcenicopterus, this character is 

 carried so far to the extreme, as to have occasioned some sy- 

 stematists to place the birds of the genus among the Natatores. 

 But the whole of the family have a membrane more or less ex- 

 tensive at the base of the toes : and if we compare the feet of 

 the common Ciconia alba, of the Platalea, and the Phce.nicopterus 

 together, we shall see a gradual increase of this membrane in 

 extent until it reaches the extreme in the latter genus. Among 

 the groups that are allied to Ciconia, there are many that resemble 

 it in general character, but deviate from it by the form of the 

 bill. Among these we may particularize Scopus, Linn., distin- 

 guished by its more compressed and furrowed mandibles ; the 

 Mycteria, Linn., where the point of the bill turns upwards ; and 

 the Anastomus, 111., where the mandibles, united at the base and 

 the point, leave an open space in the centre. The genus Tan- 

 talus, Linn, bears an evident affinity to the same group, and has 

 consequently been united to it in the arrangement of every 

 systematic naturalist. It differs chiefly by the downward curva- 

 ture of the bill. To this genus may be united the Ibis of M. La- 



* Regne Anim. i. p. 473. 



cepede. 



