368 Mr. W. P. Pycraft on the 



dass besonders auf den Raiuen viele zu Fadenfedern umge- 

 wandelte Dunen vorhanden sind. 



"Die Zalil de Schwungfedern betragt 10 Hand- und 9 



Armschwingen ; von letzteren ist die fiinfte vorhanden 



Der Hals ist ganz befiedert, ohne Seitenraine/^ 



Nitzsch's description and figures of the pterylosis of Opis- 

 thocomus are, as has been pointed out by other writers, 

 somewhat faulty ; such of his statements that I find myself 

 unable to agree with I have quoted at the beginning of this 

 section of my paper. 



As touching the pterylosis of the head, I have already 

 hinted that this is too densely featliered in his figure. The 

 spinal tract in my specimens terminates in front of the oil- 

 gland, and does not expand or surround it. The ventral 

 tract, as earlier writers have pointed out, is wrongly repre- 

 sented as dividing at the base of the neck, whilst, as we have 

 seen, this division actually takes place about midway be- 

 tween the fore and hind limbs. Nitzsch committed a much 

 more serious error when he represented Opisthocomus as 

 possessed of clavicles and a long carina sterni; a fact which, 

 to my mind, seems to prove that this author's figures were 

 drawn from a skin, in which case, as Garrod has suggested 

 (5), if he had never dissected this bii'd, he could scarcely 

 have been expected to divine the extraordinary development 

 of the crop and the consequent modification of the sternum 

 which has followed, from an inspection of the pterylosis ; 

 the fact that the sternal callosity is not indicated in his 

 drawing seems a further proof, for in the dried skin this 

 would probably suggest nothing more to his mind than the 

 scar of some old wound. 



I find the apterium spinale wider and more sharply defined 

 than is indicated in Nitzsch's figure, while the tract, instead 

 of expanding and enclosing the oil-gland, terminates as a 

 double row of feathers in front of that gland. I find 11 

 cubital remiges. 



One of the most interesting of Garrod's (5) observations 

 on this subject is the suggestion that the semiplumes cloth- 

 ing the '' unfeathered spaces '' might represent degenerated 



