24 U.S. NATIONAL MUSEUM BULLETIN 265 



riificollis, and meyerii; heavily crossbanded in the others. 4. Sex di- 

 morphism in the adult plumages, well developed in the species be- 

 ginning with meyerii, on through maculatus and xanthorhynchus, and 

 the four African species (where it is less striking in caprius than in the 

 other three). 5. The relative length of the tail, longest in the African 

 species, Avith its maximum in cupreus. 6. Total size, smallest in meyerii, 

 largest in osculans, cupreus, and caprius. 7. Differential width of the 

 bill, as exemplified in the sympatric Australian species, lucidus and 

 hasalis. 



There are also, as we shall see later in this study, remarkable changes 

 in the coloration of the egg shells; here the picture is incomplete be- 

 cause we stni have no information about the eggs of three of the species, 

 riificollis, meyerii, smdjiavigularis (to say mothing of the eggs of some 

 of the races of some of the other species). 



One point calls for some further clarification. In this summary the 

 results of the study have been outlined as if the relative chronology 

 of the species is certain and simple. It is not, and I must emphasize 

 the speculative, inferential aspect of these conculsions. To make the 

 reconstructed picture of the history of the group more comprehersible 

 to the readers of this report, personally unfamiliar with these birds, 

 it has been necessary to minimize the tentative nature of some of the 

 steps involved. The reader must be aware of the difference between 

 verbal presentation and scientific proof. On the other hand, the cir- 

 cumstantial evidence of the current 12 members of the genus Chryso- 

 coccyx points to the arrangement here outlined. A diagrammatic 

 representation of their relations, given below, suggests a certain 

 amount of multidirectional radiation, or cladogenesis, not a simple 

 progression from "primitive" to "more advanced." 



^J2.caprius 

 ,9.flavigularis — lO.klaasC 



Jl.cupreus 



7. maculatus 

 8. xanthorhynchus 



5.ruficoIlis 



/ __3.basalis 



^_ .1. malayanus 2.luci(iusc:i^^^^ 



B.meyem ~~~~— 4. osculans 



Figure 2. Apparent relationships within the genus Chrysococcyx. 



