the District of Lampong, S.E. Sumatra. 295 
Hornbill, and not to the Malayan. In the f General History 9 
(ii. p. 323, 1822) Latham mixed up his original species with 
Le Vaillant's Calao javan (l.c.) and Shaw's species founded 
on Le Vaillant's plate (Ois. d'Afrique); but the plate (xxxiv.) 
given by Latham plainly refers to the Papuan species. 
In D'Entrecasteaux's f Voyage' (ix. p. 304, t. xi.), a Horn- 
bill obtained in the Papuan island of Waigiou is figured, on 
which the title of Buceros ruficollis, Vieillot (N'. Diet. iv. 
p. 600, 1816), was founded (Temm. PI. Col. 557). But J. 
B. Forster had already (Zool. Indica, p. 40, 1781) bestowed 
the title of B. plicatus on Dampier's Ceram Hornbill. 
Vieillot's title, usually adopted for the Papuan species, there¬ 
fore ought to fall ; and that of plicatus, Forster, having pri¬ 
ority, should supersede Gmelin's title of obscurus, and La¬ 
tham's title plicatus , and stand for the Papuan Hornbill. 
Gmelin’s title obscurus and its synonym plicatus, Lath., being 
thus restored to their original owner (i. e. B. plicatus, For¬ 
ster), the oldest available title for the Malayan bird becomes 
undulatus, Shaw. 
A form very closely allied to the Malayan B. undulatus 
occurs in Tonghoo, which Mr. Blyth separated (J. A. S. B. 
1843, p. 177) under the title of subruficollis, the synonymy 
of the Papuan bird and of the Malayan being at that time 
exceedingly involved, and the species themselves not well 
known. Mr. Blyth subsequently twice identified his B. sub¬ 
ruficollis with Malayan B. plicatus (op. cit. xii. p. 991, xvi. 
p. 998), but eventually returned to his original view, and 
retained B. subruficollis as distinct (Cat. Calc. Mus. p. 320, 
no. 191). 
R. subruficollis is only to be distinguished from R. undu¬ 
latus by wanting, in the two sexes, the lateral ridges on the 
base of both mandibles, and by the bill not being so deep 
and massive. It does not possess a black transverse bar on 
the naked gular skin of either sex*, but that part in the male 
is yellow, and in the female blue, as in R. undulatus . It is 
remarkable that two such closely allied forms should coexist 
* Mr. Wardlaw Ramsay, who paid special attention to this Hornbill 
when in Burma, is quite positive on this point. 
x 2 
