Recently published Ornitholoijical Works. 499 



tci's there shown to exist in the way in which the ends of the 

 coracoid, clavicle, and scapula meet, are further investigated ; 

 and two subfamilies are formed, Falconinae and Buteoninae, 

 chiefly vipon the fact of the scapular process of the coracoid 

 meeting the scapula or stopping sliort of it when the clavicle 

 is thrust in between these bones. This arrangement places 

 in close contact the Polyhori, Falcones, Micrastures, and Her- 

 petotheres, birds widely distinct in many other respects — so 

 much so, that we feel strongly disposed to doubt the value 

 Mr. Ridgway places upon these characters in a primary 

 sense. 



Be this as it may, we are still of opinion that Mr, Ridg- 

 way's treatment of his subject is the right one; for he seems 

 disposed to bring all available characters to bear iipon it. 

 We wish we could share his confidence in submitting his 

 arrangement as really a natural one in outline ; but when 

 the value of characters has to be considered, be they genetic 

 or analogical, we cannot contemplate any such finality. 

 Mr. Ridgway has a paragraph on the importance of distin- 

 guishing between these two classes of characters, which can- 

 not be impressed too forcibly ; but there is a mental tendency, 

 of which Mr. Ridgway appears to have his full share with 

 the rest of us, to regard the selected characters in a classi- 

 fication as genetic, and the rejected as analogical. We are 

 not sure that Ave appreciate the full meaning of the paragraph 

 referred to, when read by the light of the examples. One 

 thing seems certain, that the word '' mimicry,^' as applied to 

 Pandiones and Haliaeti, is used in a sense quite different from 

 that in which it is employed by Mr, H. W. Bates in his now 

 celebrated article (Trans. Linn. Soc. xxxiii. p. 495). There 

 is, we believe, one notable case of true mimicry in Brazilian 

 Hawks of the genera Accipiter and Harpagus, Avhere the 

 Sparrow- Hawk A. pileatus wears the exact garb of the insect- 

 eating Harpagus diodon. Mr. Wallace has already alluded 

 to this instance of mimicry amongst birds, to which we be- 

 lieve we first called his attention {of. Wallace, ' On Natural 

 Selection,' p. 107). 



Mr. Ridgway is a little hard upon the systems of his 



