INSESSORES. 



193 



ences in the plumage of the adult and young birds, scarcely possible 

 in all probability to be accurately stated in many of them with our 

 present knowledge, and there are also several species that show that 

 almost peculiarly intimate relationship to which we have frequently 

 alluded in the present volume, as being found to exist in birds inhabit- 

 ing different islands or groups of islands in the Pacific Ocean. 



A close relationship appears as obvious in the present genus, as in 

 any other with which we are acquainted. It is so great, that taking 

 the TodirampliKs chloris (which is Alcedo cidorocephala, Graelin), as a 

 type of the genus, nearly all the other species so much resemble it, 

 that thej^ may almost be regarded as mere variations of the same form 

 and colors, passing through various shades only of the latter, and modi- 

 fications of size and the dimensions of the different parts of the body 

 and its members. This genus is what some naturalists would desig- 

 nate a very natural group. 



The short and sometimes very imperfect descriptions of the birds of 

 this genus, by the older naturalists, and the rarity of several species 

 in museums on account of their native localities being comparatively 

 seldom visited by voyagers, have rendered the determination of the 

 synonomy, and in fact, the recognition of some described species of 

 this group, a matter of no inconsiderable difficulty. From these causes, 

 too, confusion has arisen in the works of recent learned and reliable 

 ornithologists. 



In a future page we shall give the results of an attempt to arrange 

 this group, not without being aware of its intricate character, as we 

 hope to have shown to the reader and to our co-laborers in the great 

 field of Zoological science. We have endeavored also to have our 

 figures prepared wuth all possible accuracy. 



The bird now before the reader we regard as undoubtedly Alcedo 

 tufa of Gmelin, and Alcedo sacra of the same author (Syst. Nat. I, p. 

 453), the former being the young (Plate XV, fig. 3, of the Atlas to 

 the present volume), and the latter (fig. 1), the adult, or at least in as 

 adult plumage as we have ever had an opportunity of examining. 

 This bird (the adult), is the same species described and figured by 

 Lesson as Alcedo sacra, in Mem. Soc. Hist. Nat. Paris, III, PI. XI. 



Though Todiramphus divimis, of the same author (Memoires, as just 

 cited. III, p. 422, PI. XII), bears a considerable resemblance to the 

 young of the present species, it is quite distinct, and readily detected 

 on comparison of specimens. These species have, however, been re- 



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