660 



DR. H. GADOW ON THE REMIGES OF BIRDS. [DeC. 18, 



hidden by the outer vane of the 9th primary. This shifting explains 

 the conditions which are the rule amongst the birds of Group D. 

 The nth primary undergoes a similar dislocation in a more marked 



degree. 



Group A. — With 10 long primaries. The lOth quill is, with few 

 exceptions (e. g. Hylactes), very little shortened, and partakes 

 of the formation of the tip of the wing. The 11th quill is 

 frequently present, although small and hidden. "When it is 

 absent, at least its upper covert is present as a stiff and well- 

 developed little feather. 



To this group belong all the Passeres non-oscines. 



