450 Mr. J. H. Gurney's Notes on 



This example resembles G, but has traces of cross bars 

 visible on the central rectrices, which G has not. 



(I) Cambridge Museum. 



Contra Costa. 



This specimen exhibits in greater perfection than any 

 other that I have examined the cross-barring on the mantle, 

 each feather of which bears two transverse bars, which, as 

 well as the tip, are rufous, the interspaces being dark brown, 

 and the barring being longitudinally interrupted by narrow 

 dark shaft-marks. The general effect bears a remarkable 

 resemblance to the " milvipes " phase of G. saker : the 

 central rectrices are perceptibly, but not very distinctly, 

 cross-barred ; and all the others are transversely and more 

 strongly barred on both webs, these markings being more 

 developed on the outermost pair. 



All the shaft-marks on the under surface have assumed 

 the character of spots, mostly of an ovate form ; and the dark 

 feathers of the flanks are variegated by two whitish-rufous 

 spots on each web. 



(J) Norwich Museum. 



Wyoming (marked ($) . 



This bird is in a similar dress to that last mentioned, 

 except that in I the plumage has been somewhat recently 

 assumed, and in J the reverse is the case, the bird having 

 just begun to moult, and the old plumage being much worn 

 and faded, the effect of which is a grey tint over the whole 

 upper surface, which considerably obscures the distinction 

 between the dark brown and the rufous transverse bars, both 

 being modified by the tinge of grey, which, however, has not 

 perceptibly altered the hue of the dark narrow shaft-marks 

 on each feather of the mantle. 



Ten indistinct dark cross bars are perceptible on the 

 central rectrices. 



The general appearance of this specimen is so grey as not 

 to be altogether unlike the Australian G. hypohuca. 



Mr. Ridgway informs me that he considers this Falcon to 

 be fully adult, and that he has only seen five or six ex- 

 amples in this dress. 



