of Upupa and Irrisor. 239 



plied the name Irrisor, being a translation of Levaillant^s name 

 " Moqueur.^' This group of birds was included by Latham in 

 the genus Upupa, by Shaw in Promerops, by Vieillot in Falci- 

 nellus, by Cuvier in Merops, and by Temminck and Wagler in 

 Epimachus ; but as they differ essentially from the types of^ all 

 these genera, it is necessary to give them a distinct appellation. 

 Mr. Swainson, Mr. Vigors, the Baron de la Fresnaye, and Mr. 

 G. R. Gray restrict to this group the name Promerops of Brisson ; 

 but Brisson was wholly unacquainted with the group before us, 

 and the true type of his genus Promerops is a totally different 

 bird, called by Vieillot Falcinellus, and by Swainson Ptiloturus. 

 It is plain then that the right course is to supplant Falcinellus 

 and Ptiloturus in favour of the old generic name Promerops, and, 

 to adopt for the present group the name Irrisor as proposed by 

 M. Lesson. 



Having now settled the nomenclature of this group, I will pro^ 

 ceed to speak of its affinities, and to show first its relation to the 

 genus Upupa ; and secondly, its position in the general system 

 of Nature. 



It should be premised that the genera Upupa and Irrisor agree 

 in the form of the beak, but differ in many other particulars. In 

 Upupa the plumage is ferruginous, varied with white and black ; 

 the head is crested; the tail moderate and even, composed of ten 

 rectrices ; the feet adapted for walking ; the lateral toes being 

 nearly equal, the exterior ones divided nearly to their base ; the 

 anterior claws short and blunt, and the hinder claw lengthenecl 

 and approaching to straightness. In Irrisor, on the contrary, the 

 plumage is black with rich metallic tints, varied only with a few 

 white spots on the wings and tail ; the head is not crested ; the 

 tail is long and much graduated, composed of twelve rectrices, 

 and the feet are essentially arboreal, the outer toe being much 

 longer than the inner, and united to the middle one for the whole 

 length of the basal joint ; the hind toe is very long, and all the 

 claws are compressed, sharp, and much curved. It is evident,^ 

 therefore, that these birds must differ greatly in their habits ; and 

 accordingly we find that the hoopoe lives chiefly on the ground, 

 while the Irrisor is described by Levaillant as exclusively inha* 

 biting trees, The question then arises, whether the agreement in 

 the form of their beaks is to preponderate over the disagreements 

 of their other organs ; in other words, whether this resemblance in 

 the beaks is to be considered as indicating an affinity or only an 

 analogy. 



The majority of authors have classed the Irrisor s either amongst 

 or very near the Hoopoes. But the Baron de la Fresnaye, in the 

 ' Proc. of the Zool. Soc' for 1840*, p. 124, contends that the ge- 



* See Ann. Nat. Hist, vol. vii. p. 551. — Ed. 



