4 On the IndicatoriJte. 



at the outside, as it eonkl lianlly open its eyes, keeping them 

 almost constantly closed. The hooks apparently fall off" when 

 the bird is fully adult, although there are traces of their 

 existence in the slightly flattened end of the premaxilla, and 

 the membranous scaly appearance of the terminal portion of 

 the mandible of sevei*al adult specimens of Indicator sparrmani 

 and I. minor examined by us. The beaks of the adult speci- 

 mens of Indicator have the culmen and genys much more 

 curved than that of the young bird under discussion, and it 

 is therefore easy to see where the hooks pait from the beak, 

 and by the distinctly wielded appearance of the whole struc- 

 ture they are very obviously only superficially connected. 



The second noteworthy point about the head is that the 

 nostrils have the same swollen appearance as those of young 

 Cuckoos, but instead of being rounded as in the Cuculidse, 

 they are of an elongated ovate form, appearing more in the 

 form of slits. 



B. Pterylosis. — The following description is taken from 

 the specimen of Indicator variegatus alluded to in the preced- 

 ing chapter : — 



Pteryla capitis. Calls for no comment except that the feather- 

 follicles are very minute, and their presence is only 

 known by the shading in the skin. 



Pt. spinalis. This is a very narrow tract and ill-defined until 

 the back is reached. Indeed from its juncture with the 

 Pt. capitis it is represented only by a dark shading in 

 the skin, which is so faint at the part left blank on the 

 sketch as to be almost invisible, even with a strong 

 magnifier. On the back it assumes two branches, some- 

 what triangulated on the outer edges, but the true rhombic 

 saddle and lanceolate space mentioned by Nitzsch have 

 not yet been formed. Where the rhombic region ends, 

 the young feather-follicles are plainly visible. 



Pt. liumerales. The humeral tracts are very sharply defined 

 bands, and consist of very well developed follicles. 



Pt. alaimm. These are also well defined, and do not differ 

 from Nitzsch's figure of the adult Prodotes. 



