HYDROCORAX SEMIGALEATUS 



SEMI-HELMETED HOENBILL, 



Buceros semigaleatus, Tweeddale, Proc. Zool. Soc. (1878) p. 279. 



Hab. Ampavo, island of Leyte, and Panaon, Philippines (Everett). 



This local form of H. planicornis was described by the late Marquis of Tweeddale (I. c.) from 

 specimens procured by Mr. Everett at Ampavo, in the extreme south of the island of Leyte, and 

 on Panaon, both belonging to the Philippine archipelago. In the colouring of the bill and 

 plumage this bird presents no difference from H. mindanensis ; and its claim for specific 

 distinction rests solely on the shape of the casque. This, instead of being flat upon its superior 

 plane and terminating in a compressed and elevated anterior margin at a right angle to the 

 culmen, like those of H. planicornis and JET. mindanensis, has this portion arched, and the 

 crown of this arch upon its anterior half forming an acute ridge, while the casque itself falls 

 away anteriorly, and is lost in the culmen. In the two species mentioned above, the contour of 

 the plane of the casque is oval, with the posterior end rounded, and the anterior pointed. In 

 this bird the posterior end is rounded, and the sides are parallel for two thirds the length of the 

 casque, where they form corners, and then recede rapidly to the culmen. Nothing was recorded 

 regarding the economy or habits of this peculiar form, though several specimens were procured, 

 representing the adult and immature birds. The plumage of the old individuals was the same 

 as that of H. mindanensis, with which this form is most closely allied. The iris appears to vary 

 in colour, that of a male from Leyte being light yellow, while one from Panaon was pale blue. 

 Orbital skin almost black; gular skin indian-yellow ; feet coral-red, nails dark brown-grey. At 

 the base of the mandibles of adult examples there are slightly corrugated plates. 





Male. — Length of wing 15'80 inches, tail 15, tarsus 2'20, bill at gape 5*85 ; length of casque 

 4*90, breadth 2, sides 3*35. 



Female. — Length of wing 14*30 inches, tail 14*50, tarsus 2*20, bill at gape 5*30; length of 

 casque 4*75, breadth 1*65, sides 3*30. 



The young in first plumage have the head, neck, breast, abdomen, thighs, and vent greyish 

 fulvous-white, the feathers being ferruginous at their insertions, and grey at their tips. Upper 

 tail-coverts also same colour, with brown bases. Back and wings brown ; quills dark brown 

 with greyish fulvous edgings. Median pair of rectrices pale brown for two thirds their length, 

 with the apical third creamy white; remaining rectrices pale rusty-brown. Bill black, with 

 the tip yellow. Iris dark brown ; orbital skin greenish yellow ; gular skin yellow ; legs and feet 

 dark orange. 



The figures in the Plate are taken from the type specimens in Captain Bamsay's possession, 

 to whom I am indebted for the opportunity of introducing them into this work. 





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