I/ABRID-ZE. 
85 
Family L ABRIDGE. 
XIPHOCHILUS, BleeJc. 
293. Xiphochilus robustus. Plate XII. fig. 3. [667.] 
Xiphochilus robustus, Giinth. Fish. iv. p. 98. 
This species is sufficiently described in Giinther’s Catalogue of Fishes. In the specimen 
from Zanzibar the formula of the dorsal fin is ~ , and in that from Mauritius ^ ; in the 
latter specimen the twelfth spine is turning into a ray, the lower half being spinous 
and the upper half articulated, but not branched. 
Colour in life. — Upper part fawn, lower white. A broad whitish oblique band 
ascending from the root of the pectoral to the back of the tail behind the termination 
of the dorsal ; on the upper margin of this band the colour of the body is darker ; each 
scale, except on the band and lower part of the body, has an indistinct pale-blue vertical 
line. Lips cobalt-blue ; a similarly coloured line through the centre of the orbit, 
another along its base, and a third below it ; a blue line on the operculum, parallel to the 
posterior limb of the prseoperculum ; opercular membrane blue. Five or six longitudinal 
blue lines on the tail. Dorsal yellowish, with blue margin and base and a band of blue 
marks along the middle. Anal yellowish, with a series of blue spots along base, a 
bluish margin, and a very distinct yellow intramarginal band. Caudal with blue lines 
along the rays ; ventrals and pectorals pale fawn. 
Length 11 inches. 
Zanzibar. Mauritius. 
294. Xiphochilus gymnogenys, sp. n. Plate XII. fig. 4. [198.] 
D. A. ~. L. lat. 29. L. transv. 2^/11. 
Diagnosis. — The greater part of cheek and of sub- and interoperculum naked ; 
but there is a patch of small scales, as large as the eye, below its posterior edge. Hind 
part of gill-cover produced into a long flexible flap, fitting above the axil of the pectoral. 
Interoperculum extremely broad, flexible, partly covering its fellow below the throat. 
Description. — Xipliochilus robustus , and still more X. gymnogenys , form a transition 
between this genus and Chcerops , the pharyngeal bones of X. gymnogenys bearing a 
much greater resemblance to that genus than to X. typus. 
The height of the body is contained nearly four times, and the length of the head 
nearly three times and two-thirds in the total length. The maxillary does not reach to 
the anterior margin of the orbit. Prseorbital much higher than the orbit. Cheek 
naked, with the exception of a patch of scales below the posterior margin of the eye. 
The posterior margin of the prseoperculum very slightly denticulated ; the operculum. 
