CATALOGUE. 
593 
its outer feather 3 in. less ; bill from gape 4f in., from hindmost part 
of casque to point of bill, in a straight line, 6 in. ; height from chin 
to top of casque, 3 in. 
Presumed adult female has the superciliary coronal circle repre- 
sented by obscure silvery-greyish. Length of wing 13|^ in., of tail 
16 in., outermost feather 4 in. less ; bill from gape 5^ in., length of 
casque 5 in., height from chin to top of casque, 3 in. The casque 
in both birds is allied in shape to that of H. alUrostris and H. con- 
vexa^ and is of a different form to that of S. nigrirostris. 
The female, according to Dr. Cantor's Notes, has the " iris 
greyish-brown, bill yellowiKsh-white, or buff, naked space round the 
eyes livid, feet black." 
873. HYDR0CI8SA (?) NIGRIROSTRIS, Blyth Sp. 
Buceros nigrirostris, Blyth, J. A. S. Beng. XVI. p, 995 
(1847); XVIII. p. 803; XXIV. p. 272; Cat, B. 
Mus. A. S. Beng. p. 44. 
Buceros malayanus, apud Lord Hay, Madr. Journ. XIII. 
pt. II. p. 151. 
Quay- Quay, Malays, Cantor. 
The Black-billed White-browed HornbiU. 
a. b. ^ $ . Malacca. Presented by Dr. Cantor. 
Plumage, in the presumed male, glossy greenish-black above, in- 
cluding the chin and throat, which, and the under-parts, are less 
glossy ; head adorned with a broad yellowish-white superciliary 
coronal circle ; tips of the four outer tail-feathers yellowish-white ; 
space round the eyes and basal angle of lower mandible, naked, and 
in the dry skin, yellowish. Presumed female, as in male, excepting 
that the superciliary circle is represented by obscure silvery-greyish ; 
bill and casque blackish; "and in the young," says Mr. Blyth, 
" white. The form of the casque is low, thinly compressed towards 
the front, and abruptly truncate anteriorly, with a longitudinal ridge 
on each side, in old birds, occasioning a broad shallow groove above 
and another below it." 
Length about 20 in., of wing llf in., tail to tip of middle feathers, 
13 in., to tip of outer feather 10^ in., bill from gape 4f in., length of 
casque 3 in., height from chin to top of casque 2^ in. 
Mr. A. E. "Wallace states, in a letter from Singapore (Ann. Nat. 
Hist., Peb. 1855), that K. nigrirostris is the female of H. malayanus, 
