





RHYTIDOCEROS SUBRUFICOLLIS. 



BLYTH'S WEEATHED HOKNBILL. 



Buceros subruficollis, Blyth, Journ. Asiat. Soc. Beng. (1843) vol. xii. p. 177, (1849) p. 320; Barbe, Journ. Asiat. 



Soc. Beng. vol. x. p. 922. 

 Buceros plicatus, Blyth, Journ. Asiat. Soc. Beng. vol. xii. p. 991, vol. xvi. p. 998; id. Cat. Birds Mus. Asiat. Soc. 



(1849) p. 45 (nee Forster). 

 Rhyticeros subruficottis, Horsf. & Moore, Cat. Birds Mus. E.-Ind. Co. (1856-8) vol. ii. p, 600.no. 883; Hume, 



Nest & Eggs Ind. Birds, pt. i. (1873) p. 115; id. Str. Feath. vol. ii. (1874) p. 470; Ramsay, Ibis (1877) 



p. 455. 

 Rhytidoceros subruficollis, Cab. & Hein. Mus. Hein. (1860) Th. ii. p. 172. no. 474; Tweeddale, Ibis (1877) p. 295. 

 Buceros (Rhyticeros) pusaran, Tickell, Ibis (1864) p. 180. 



Buceros (Rhyticeros) subruficollis, Gray, Hand-1. B. (1870) pt. ii. p. 129. sp. 7886. 

 Aceros subruficollis, Blyth, Cat. Mamm. & Birds Burma, (1875) p. 69. sp. 72. 



Hab. Arakan, Tenasserim Provinces (Blyth) ; Southern Shan States of Siam (Tickell) ; Lawas river, N.W. 

 Borneo (Ussher). 



This bird was separated by Blyth from the well-known B. plicatus, Porst., on account of the 

 base of the mandible being smooth and without the transverse ridges so conspicuous in Eorster's 

 species. In B. subruficollis the mandible never possesses at any age of the bird this roughened 

 surface. As this difference appears to be a permanent one, it would seem to be sufficient to give 

 the two birds distinct specific rank. Their geographical distribution also is not the same, the 

 present species ranging rather more to the northward than its ally, and never going into the 

 Malayan peninsula. B. subruficollis may also be distinguished by never having the black 

 transverse bar on the gular skin of either sex, that part being yellow in the male, blue in the 

 female. Lieut. Wardlaw Ramsay observed this difference between the species to have been con 

 stant in a large series of examples collected by him in the district of Tonghoo, Tenasserim. 



In regard to the curious scaly casque possessed by this bird and its allies, Mr. Blyth found, 

 after examining numerous specimens, that in no instance did the number of transverse ridges 

 exceed seven ; and he deemed it obviously apparent that they scaled off anteriorly as they were 

 pushed forward by the growth of those at the base of the maxilla. 



Tickell says, speaking of this bird under the name of B. pusaran, that it is very numerous in 

 the Tenasserim Provinces and in the inland forests of Arakan. Its voice is a short gruff croak 

 like " kukkuk," repeated at intervals. The flight is slow and regular, capable of being continued 

 for a great distance ; and the noise made by the air rushing through the feathers of the wings is so 



