1878.] BIRDS OF THE SANDWICH ISLANDS. 349 



of the generic group Pandion designated Polioa'etus by Dr. Kaup.' 

 (Fide op. cit. p. 98.) 



" Mr. Ridgway, on the contrary, after an examination of the type 

 specimen, wrote to me that he considered it ' a Buteonine form dif- 

 fering from the true Buteones only in the system of coloration, 



which reminds us somewhat of Milvago ckimachima.' 



" In the specimen brought home in the ' Challenger ' there is much 

 less resemblance to the coloration of M. ckimachima, and nothing, 

 in my opinion, to justify the removal of this species from the genus 

 Buteo. 



" The following is a comparison of the measurements of the Chal- 

 lenger example with those of the type specimen as given by Mr. Cassin 

 in the work to which I have referred : — 



Type specimen 'Ch alien ger' specimen 



(sex unknown). (female). 



inches. inches. 



Total length of skin 17 (above) 1 77 



Wing 12 12 



Tail 7'5 7-2 



Bill from gape 1*5 1*5 



Tarsus 275 2"8 



Hind toe and claw 1*75 2*2 



Middle toe s. u .... P7 



Claw of ditto 0-8 



Culmen (exclusive of cere) . . .... 1-1 



Cere 0-4 



" Mr. Cassin describes the type specimen as having ' the third, 

 fourth, and fifth quills longest and nearly equal,' which agrees with 

 the ' Challenger ' specimen, as does his description under the head 

 of 'form' generally ; but I think that, in speaking of the toes as 

 having ' their under surfaces strongly corrugated or pustulated, 

 claws very large, long, and curved,' he uses rather stronger language 

 than is strictly applicable to the ■ Challenger ' specimen, though in 

 this the under surface of the feet is certainly somewhat corrugated 

 and roughened, and the claws are slightly longer than in Buteo vul- 

 garis or in Buteo desertorum. 



" As regards the difference of coloration in the two specimens, Mr. 

 Cassin describes the type as having the 'head and entire underparts 

 and upper tail-coverts yellowish white, all the feathers being pure 

 white at their bases and widely terminated with pale yellowish, more 

 distinct on the breast and tibiae.' 



" In the ' Challenger ' bird the upper part of the head is dark 

 wood-brown like the mantle, except that some of the feathers, espe- 

 cially on the crown and forehead, are partially edged with yellowish 

 white ; on the sides of the head these white edgings are more con- 

 spicuous ; the throat is white ; the breast, abdomen, under tail- 

 coverts, flanks, and wing-linings are white, slightly tinged with buff, 

 especially on the tibiae, and more or less mingled with wood-brown 

 throughout, except on the lower abdomen and tibiae, the brown pre- 



