240 Mr. H. E. Strickland on the Structure and Affinities 



nera Upupa and Irrisor (or as he terms it, Promerops,) have in 

 reahty no near affinity to each other. He argues that birds have 

 in many cases been arranged artificially in consequence of authors 

 being guided solely by the form of the beak without attending to 

 the structure of the other organs. After pointing out the marked 

 differences between the feet of Upupa and those of Irfisor, he 

 concludes that Upupa has evident affinities with the larks [Alau- 

 dinoi), but that its true position is in «, special family of the Te- 

 nuirostres, in conjunction with Upucerthia and some other allied 

 S. American genera. The genus Irrisor j on the contrary, he con- 

 siders to belong to the Cinny7id<2, or as they are more correctly 

 called, iVec/«rmMV/«^, to which they have much resemblance in their 

 glossy plumage. 



Now it is undoubtedly true that the most unnatiu-al classifi- 

 cations of birds have in many cases resulted from the beak being 

 taken as the sole ground of arrangement, to the exclusion of the 

 other organs. I do not however think that the juxtaposition of 

 Upupa and Irrisor is really an instance of such a vicious arrange- 

 ment, and I hope to show, that notwithstanding the disagreements 

 in their feet, tail and plumage, these two genera are in reality 

 very closely allied. 



It will generally be found that when several genera of remote 

 affinity have been brought together in consequence of a resem- 

 blance in the form of their beaks, that resemblance is more ap- 

 parent than real, consisting in a general and superficial agree- 

 ment in the form and outline, while the minor details of structure 

 present differences which at once indicate the true affinities of 

 the respective groups. Thus the genus Sq/thropswas till very lately 

 classed by all authors among the toucans, on account of the ge- 

 neral resemblance of the beak, while if the slightest attention had 

 been paid to the position of the nostrils, it would have been seen 

 at once that its true place is among the cuckoos. A similar su- 

 perficial resemblance in the beak has caused Tichodroma to be 

 classed with Certhia instead of with Sitta, Spermophila with Pyr- 

 rhula instead of with Guiraca, Oredica and Falcunculus among the 

 LaniincB instead of the Parince, and numerous other cases which 

 might be quoted. 



On comparing Upupa with Irrisor, however, we find a coinci- 

 dence of structure not only in the general forms, but in the mi- 

 nutest details of the structure of their beaks ; and what is of still 

 greater importance, the beaks of these two birds present certain 

 characters which are found in no other group of birds with which 

 I am acquainted. 



Upupa and Irrisor both present to us the remarkable combi- 

 nation of a very long beak with a very short tongue. The two 

 mandibles are for three-quarters of their length perfectly solid, 

 the surfaces of contact being smooth and flat ; while in all other 



