THE TANGANYIKA PROBLEM. 
1 86 
in length of snout, 5 times in length of head, and 1.$ in. interocular width ; eight 
series of small scales on the cheek ; larger scales on the opercle. Eighteen 
gill-rakers on lower part of anterior arch. Dorsal XVII. 16 ; spines subequal from 
the fifth, which measures \ length of head ; longest soft rays J length of head. 
Pectoral pointed, f length of head. Ventral not half as long as the distance 
between its base and the vent. Anal III. 18; spines very weak. Caudal forked. 
Caudal peduncle twice and a half as long as deep. Scales very small, 140 in a 
11. . 75. 
longitudinal series above the upper lateral line, — in a transverse series; lat. 1 — ' 
Brownish above, white beneath ; a series of large, rounded blackish spots on each 
side of the back above the lateral line, alternating with a series of vertical blackish 
bars on each side of the body ; on the tail, from the middle of the soft dorsal, the 
spots unite into a band which extends to the caudal, and the vertical bars likewise 
fuse to form a lateral band ; a blackish spot on the opercle, another at the base of 
the ventral ; two black bands on the dorsal, a basal and a marginal. 
Total length, 340 millim. 
Described from a single specimen from the west coast at Tembwi. 
This second species of the remarkable genus Bathybates differs from its congener 
in the smaller eye, the more numerous gill-rakers, and the smaller scales. 
52. Pelmatochromis polylepis. — Blgr. 1900. 
Depth of body 2 h to 2% times in total length, length of head 3 to 3J times. 
Snout with straight upper profile, 1 ■' times diameter of eye, very deep, its length 
not exceeding the width of the prreorbital region ; diameter of eye 3! to 3^ time 
in length of head, equal to or a little greater than interocular width ; maxillary 
extending nearly to below anterior border of eye ; teeth very small, in four or five 
irregular rows in both jaws, the outer somewhat larger ; four or five series of scales 
on the cheek ; larger scales on the opercle. Gill-rakers short, lamellar, denticu- 
late, 14 or 15 on lower part of anterior arch. Dorsal XV. -XVI. 14-15; spines 
subequal from the sixth, which measures 1 or a little more than J length of head. 
Pectoral pointed, falciform, at least as long as head. Ventral reaching vent, the 
outer ray produced into a filament. Anal III. 8; third spine much stronger than 
dorsal spines, nearly i length of head. Caudal rather deeply emarginated. Caudal 
6—7 
peduncle a little longer than deep. Scales with denticulate border, 55-58 3 ; 
~W 
lat. 1 
25—31 
47 4s’ u PP er extending to below the last spines or the first soft rays of 
the dorsal, the lower originating a little behind the shoulder and extending to the 
caudal fin. Body golden, olive on the back, purplish streaks along the dorsal and 
caudal fins, sometimes forming a wide-meshed network. 
Total length, 300 millim. 
53. Ectodus descampsi. — Blgr. 1898. (Fig., p. 179, lower.) 
Depth of body 3J times in total length, length of head 3. Snout short, with 
curved upper profile, slightly shorter than the eye, the diameter of which is 2 \ in 
