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Proceedings of the Royal Society 
the middle of front of lower jaw. Maxillary teeth in front of upper jaw, 
small, short, thickly set in a broad band. 
Barbels: — Maxillary barbels , dark-coloured, much longer than head, 
reaching more than half way down pectoral spines; edged with a broadish 
membrane interiorly. Mandibular barbels. — Outer, dark-coloured, slightly 
fimbriated or fringed, reaching to base of pectoral fin. Inner, light-coloured, 
about half the length of outer, and more distinctly fringed. 
Dermal bones of head and neclc. — Broad, rough or granular ; terminate 
in front of eyes in forked processes; broad behind, and extend in a pointed 
process a little beyond each side of base of dorsal spine. Humeral 
process. — Much longer than high, pointed behind, runs nearly as far back 
as nuchal plate, granular surface, a slight projecting ridge along anterior 
margin, and a thick, somewhat smooth, and tapering ridge projects along 
its inferior border. 
Fins rather small : — D. 1/8. A. 12. P. 1/7. (V. 7.) 
Dorsal fin. — Spine shorter than the head (fixed upright), almost smooth 
in front, showing only some very obscure indications of a few short pro- 
cesses or teeth at upper part ; toothed at upper part behind, teeth directed 
somewhat towards base of spine ; (a small soft ray or filament inserted a 
little below the point.) First five rays (the third the longest) as long as 
spine and filament together. Adipose fin. — Elevated; longer than head; 
space between it and dorsal, about equal to length of base of dorsal fin 
without spine. Pectoral fin. — Spine larger and longer than dorsal, toothed 
on both sides ; teeth small and thickly set together on outside, directed 
towards extremity of spine; teeth larger and more apart on inner side, and 
point towards base of spine; fin reaches a little beyond base of dorsal fin, 
but not to base of ventral fins. Ventral Jins. — Small; in length pass anal 
opening, but do not reach to base of anal fin. Anal-fin. — Larger than 
ventral. 
Tail. — Forked nearly half the depth of rays; two uppermost rays pro- 
duced about a third beyond others. 
Colour (in spirits). — Pale brown, slightly blotched or mottled with 
darker, especially on head, at insertions of fins and tail, and on rays of fins 
and tail. Ventrals and anal fin nearly black. Spines light coloured. 
Total length of fish without caudal rays, 4| inches; to extremity of 
elongated caudal rays, 5-| inches. From point of snout to posterior extre- 
mity of nuchal plate (lg inches), fully a third of total length to extremity 
of elongated caudal rays. Total length of specimen, 5-f inches. 
Captured at Ikorofiong, Old Calabar Biver, West Coast of Africa. 
I have named the fish after the Rev. Alexander Robb, D.D., to 
whom I am indebted for these specimens, as well as various others, 
from the Old Calabar district of tropical Africa. 
Dr Robb tells me there are great difficulties in the way of getting 
