127 



bably Java, — the Elanus axillaris inhabiting Australia, and perhaps 

 extending its range to Java (he said perhaps, because a slight 

 difference is observable betvpeen the only Javan specimen he had seen 

 and those from Australia), and the fine Elanus inscriptus having 

 been hitherto found only in Australia. To these he now added, to the 

 Old World a fourth species, and to the entire group a fifth, by cha- 

 racterizing a fine bird from Celebes as Elanus hypoleucus. This new 

 species is one of the largest members of the genus, and is rendered 

 conspicuous by the entire under surface being white, even the basal 

 half of all the primaries being of this hue, — in which respect, and in 

 its larger size, it materially differs from the E. melanopterus, the 

 only bird with which it could be confounded. 



Elanus hypoleucus, Gould. 



Adult. — Face, space over the eye, ear-coverts, all the under sur- 

 face of the body, under tail-coverts, under surface of the tail feathers, 

 and the thighs, pure white ; the under surface of the wing is also 

 pure white ; basal half of the under side of the first six primaries 

 white, slightly speckled with grey, passing into blackish grey ; on 

 their apical halves this grey hue also pervades the under surface 

 of the remaining primaries ; crown of the head, back of the neck, 

 back, and scapularies, deep grey ; on the shoulders a large patch 

 of black ; secondaries and basal half of the primaries deep grey, 

 passing into blackish grey at their tips ; two centre tail feathers 

 grey above, the next on each side grey on their outer margins, the 

 rest white ; cere and legs orange yellow ; bill and nails black. 



Total length, 14 inches ; bill, 1|^ ; wing, \2\ ; tail, 6|- ; tarsi. If. 



Young. — At apparently about nine months old differs from the 

 adult in having the crown lineated with reddish brown, and a cres- 

 cent of white at the tip of the primaries, secondaries, scapularies, and 

 wing-coverts. 



Hah. Vicinity of Macassar, Celebes. 



Remark. — The above description of the adult is taken from a 

 fine example in the possession of J. H. Gurney, Esq., which, as well 

 as the young bird in the possession of Mr. Gould, was collected by 

 Mr. Wallace. 



Dr. Crisp exhibited a hen, six years of age, that had taken on the 

 plumage of the cock ; the bird also had spurs an inch long. On 

 dissection, the ovary was found converted into a hard cartilaginous 

 mass of uniform consistence. He placed the specimen before the 

 Society, not because this abnormal state of the ovary, and consequent 

 change of external character, was of rare occurrence, but rather for 

 the purpose of ascertaining whether such changes of plumage oc- 

 curred in birds living in a state of nature. Dr. Crisp had seen them 

 in the Hen, tame Duck, and common Pheasant ; but the last-named 

 bird in this country could scarcely be called a wild bird. 



There was one curious physiological deduction which he might 

 notice : viz. that when quadrupeds were castrated (young), they 



