720 Dr. J. A. B. de Haan on Central [Ibis, 



XXVI. — On a f)ouhlin(j of the Central Tail-feathers in a 

 Bird-(f-Paradise. By Dr. J. A. Bierens de Haan 

 (Amsterdam), 



(Text-figures 1 & 2.) 



Half a century ago Von Rosenberg wrote in the Nat. 

 Tijdschr. voor Ned. Indie, xxix. 1867, that as a rare 

 exception males o£ Paradisea apoda were found with three, 

 instead of two, wiry median rectrices. Such males would 

 be called " Radjahs " or Kings of the Paradise-Birds by the 

 natives of the Aru Islands. Rosenberg succeeded in cap- 

 turing such a specimen. It was sent to Leydeu, and 

 afterwards described by Schlegel (in the ' Museum d'Hist. 

 nat. des Pays-Bas,' 18()7) as a " variete tres curieuse." 



However, the matter did not attract much attention. 

 Neither Elliot nor Sharpe mentioned it in their Monographs 

 on the Birds-of-Paradise ; Salvadori alone refers to it in his 

 ' Ornithologia della Papuasia ' (1881), but remarks that he 

 cannot suppress the suspicion " die si tratti di cosa arti- 

 ficiale." 



In the Zoological collections of the " Handelsmiiseum van 

 het Koloniaal Instituut" at Amsterdam (the former Colonial 

 Museum at Haarlem) I found a mounted male specimen of 

 the small Bird of-Pai-adise {P. minor) that showed an ab- 

 normality of the same kind. The tail^ that has normally 12 

 feathers, here had 14, of which 4, instead of the normal 2, 

 were produced into the well-known thread-feathers. That 

 the case was not an artificial one was clearly visible on a 

 more exact examination of the insertion of those feathers. 

 In fig. 1 the normal insertion of the tail-feathers is shown 

 after removing the coverts. The ten normal rectrices (?') 

 appear on the same level on both sides ; the two central 

 thread-leathers (r') with their white shafts arise on a higher 

 level from a knob (/;), and are surrounded for a short 

 distance by a kind of horny cover [h) as a continuation of 

 that knob. In fig. 2 the insertion in the abnormal case is 

 shown. The knob (k'), from which the four wiry feathers 



