INTRODUCTION. 



xxi 



^ 



$ 







on the other hand, places these birds nearest the Kingfishers, because, on account of the structure 

 of the feet and toes, and also from their habits, the Hornbills are Pissirostral birds, though of an 

 abnormal form. " Their very short legs and united toes, with a broad flat sole, are exactly similar 

 to those of the Kingfishers. They have powerful wings ; but their heavy bodies oblige them to use 

 much exertion in flight, which is therefore not very rapid, though often extended to considerable 

 distances." "We look upon Hornbills, therefore, as one of the abnormal developments 

 of Pissirostral birds, of which they are the largest, the least elegant, and the least gifted with 

 faculties for locomotion and for obtaining food ; and their nearest affinities lie in the direction of 

 the Kingfishers." Nitzsch, in his ( Pterylographie '*, places the three genera Buceros, TJpupa, 

 and Alcedo in his family Lipogloss^e, agreeing together in the absence of an aftershaft on the 

 contour feathers, and in the feathered tip of the oil-gland, but differing in the characters of their 

 plumage and in the distribution of their feather-tracts. Buceros and Upupa agree in having ten 

 rectrices ; Alcedo has twelve. Eytonf makes the Bucerotid^e consist of three subfamilies, Momo- 

 tince, UpupincB, and Bucerince. Prof. Huxley J, in his paper on the classification of birds, places 

 the Bucerotidje in the Desmognathous division of the Carinate, and arranges them between 

 Podargus, Alcedo, and Dacelo; while Dr. Murie §, in his able paper on the Upupid^b and their 

 relationships, considers the members of that family to be the nearest allies of the Hornbills. He 

 says, in concluding his remarks, " Lastly, what in exterior appearance can be more opposed to 

 each other than such a great unwieldy horned bird as the Rhinoceros Hornbill (Buceros 



rhinoceros) and the graceful Hoopoe ? Yet when Tockus is reached, size and outward 



peculiarities dwindle till we have a form in which can be recognized semblance to certain of the 

 UpuprD^E. There is still a gap; but the very manifold structural agreements and adaptations 

 thereof to habits &c. are strong evidences of congruity ..... It suffices to say that economy in 

 general, pterylosis, geographical distribution in part, and anatomy taken all in all, turn the scale 

 in favour of the Hornbills as the group bearing the closest relation to the Hoopoes and Irrisors." 

 It will be seen by the foregoing references that the chief writers on comparative anatomy have 

 nearly agreed in the position which this family should occupy among birds, and that the 

 Kingfishers on one side and the Hoopoes on the other are apparently its nearest allies. It must 

 be borne in mind that, although the number of their rectrices are different, yet many of the 

 habits of the Hornbills and the Kingfishers are very similar ; and in the classification of birds 

 these should always have considerable influence in forming an arrangement. The Hornbills as 

 they exist at the present day, exhibit to us probably but a remnant of the great family which 

 once dwelt amid the forests of that mighty eastern continent of which a large portion is now 

 beneath the waters. So, many gaps exist, not one only, we may presume; and the diversified 

 forms that would supply the necessary links to complete an unbroken chain of connected species 

 throughout the family have long since disappeared. Our means, then, for working out this 

 difficult problem are but scanty ; but probably, amid this ever-shifting, changing world, they will 

 never be more ample than at the present time. 



* Ray Soc., edited by Sclater, 1867. 

 % Proc. Zool. Soc. 1867, p. 446. 



t Osteol. Av. (1867) p. 59. 

 § Ibis, 1873, p. 181. 



/ 



