16 MR. G. A. BOULENGER ON A COLLECTION 
especially below the lateral lines, 78 4 ag; lat. & = ; the upper extending from the opercle 
to the caudal, the lower from below the last dorsal spines to the caudal. Pale bluish 
green, iridescent above, white below; dorsal and anal bluish grey; ventrals and caudal 
yellowish ; pectorals yellow ; two dark streaks on the dorsal. 
Total length 275 millim, 
A single specimen from Kinyamkolo, taken at a depth of 400 feet. The specimen 
is a female with ripe ova; these are of large size, measuring 3} millim. in diameter. 
The stomach contains a small, partially-digested fish of the genus Paratilapia, as 
first ascertained by a sciagraph kindly prepared by Messrs. Gardiner and Green, 
which has enabled me to compare the structure of the vertebral column with that of 
other members of the family Cichlide. The insertion of the ribs is typical, viz., 
sessile, except on the last three preecaudal vertebre ; the transverse processes are short 
and in front of the ribs. The number of vertebrae agrees with that of the more elongate 
species of Paratilapta. 
ERETMODUS, g. 0. 
Body moderately elongate; scales ctenoid. Jaws with rather large spatulate teeth 
with truncated crowns disposed in oblique transverse rows of two or three. Lips much 
developed; maxillary entirely concealed when the mouth is closed. Dorsal with 
23 to 25 spines; soft rays reduced to 3 to 5; anal with 5 spines. Vertebre 30 
(15+15). 
A strongly aberrant form, remarkable for its dentition and the structure of the dorsal, 
formed almost entirely of spines. 
17. Erermopus cyanostictus, sp. n. (Plate III. fig. 5.) 
8 or 10 transverse series of teeth in each jaw, the crowns reddish brown. Depth of 
body equal to length of head, 3 times in total length. Profile of snout curved ; length 
of snout 1} to twice diameter of eye, which is 44 to 5 times in length of head, and 
a little less than interorbital width; mouth extending to below nostril; cheeks and 
opercles naked. Gill-rakers short, 9 or 10 on lower part of anterior arch. Dorsal 
XXIII-XXV 3-5; spines subequal from the sixth, + length of head, a little shorter 
than soft rays. Pectoral ? length of head. Ventral reaching vent. Anai III 6-7; 
third spine longest, a little longer than dorsals; soft rays about 3 Soe of head, 
Caudal rounded. Caudal peduncle deeper than long. Scales 32-35 45; lat. 1. = aus 
Blackish brown, with scattered pale blue dots; belly yellowish. 
Total length 75 millim. 
Five specimens from Mbity Rocks, and three from Kinyamkolo. 
The toothed portions of the premaxillary and mandible are much developed in depth, 
in a manner suggestive of the Sparidw and Scaride, and the teeth are implanted in 
sockets. The deep triangular groove for the reception of the premaxillaries extends 
