﻿CLASSIFICATION. 



xvii 



species appears to differ wonderfully in plumage, some of the stages being given in the 

 present work ; but it is difficult to determine, in the present state of our knowledge, which is 

 the very old bird ; for they differ conspicuously even when all traces of young plumage have 

 disappeared. The other subdivision of the cinnamon-coloured section contains three species, 

 two of which have been long known to science, and have been made the types of the genera 

 Caridagrus and Astacophilus of Messrs. Cabanis and Heine. The third species, //. hombroni, 

 is at present only represented by the unique specimen in the Paris Museum. The next 

 section contains several species, all of which seem to have two forms, a bright- and a dingy- 

 coloured representative. Thus H. julice is the dull-coloured representative of //. sacra, 

 H. sordida of H chloris, and H. vagans of H sancta. The habitats of these dark-coloured 

 forms are always distinct ; and I have therefore no hesitation in keeping them separate. Of 

 the first section of this green group of the genus Halcyon there are two species, which have 

 a very distinct superciliary cincture encircling the head. Of these Halcyon sacra is, as far 

 as I can see, the Polynesian representative of H. albicilla ; for in some stages of plumage, 

 where the head gets white, they must be very hard to distinguish ; yet the young are 

 totally different, as will be seen by a reference to the Plates given in the 'Monograph.' 

 H julice is only a dark-coloured representative of H. sacra, and bears the same relation to 

 that species that H. sordida does to H. chloris and H. vagans to H. sancta. The last-named 

 birds call for little remark ; and so we have only to notice the remaining species of the 

 genus, which stands quite alone : this is H. funebris, readily to be distinguished by its dark 

 brown (sometimes black) head and back. 



Genus 12. Dacelo. 



Dacelo, Leach, Zool. Misc. ii. p. 125 (1815) 



Paralcyon, Gloger, Fror. Notiz. p. 278 (1827) 



Choucalcyon, Less. Traite d'Orn. p. 248 (1831) 



Nycticeyx, Gloger, Handb. d. Naturg. p. 338 (1842) . . . 

 Sauromarptis, Cab. & Heine, Mus. Hein. Th. ii. p. 163 (1860) 



Type. 

 D. gigas. 



D. gigas. 



D. gigas. 



D. gigas. 



D. gaudichaudi. 



I. 



gigas. 



Clavis specierum. 



a. Scapularibus brunneis. 

 a'. Sexibus similibus : pileo medio rufescenti-brunneo, utrinque albido : 



cinctu nuchali brunneo 



V . Sexibus dissimilibus, mari cauda cyanea a fcmina, (cauda rufa) 

 distinguendo : pileo distincte striato. 



a". Subtus albescens, fasciis parvis brunneis 



b". Subtus cervinae. 



a'". Pogonio externo rectricis extimi maris albo baud fasciato . 

 b 1 ". Pogonio externo rectricis extimi maris albo distincte fasciato 



b. Scapularibus nigerrimis. 



a. Pileo nigro 5. gaudichaudi 



b. Pileo nigro ochracco punctato 6. tyro. 



2. leaclii. 



3. cerrina. 



■1. occidcntalis. 



