new Fishes from the Upper Congo. 423 
in total length, length of head 2? times. Snout as long as 
diameter of eye, which is 83 in length of head and equals 
interorbital width; maxillary extending to below anterior 
third of eye; 4 series of scales on the cheek ; opercle naked (?). 
Gill-rakers long and slender, about 20 on lower part of ante- 
rior arch. Dorsal XIII 11; spines subequal from the sixth, 
nearly 4 length of head and 2 longest soft rays, which are 
produced and filiform. Pectoral as long as head. Ventral 
with produced outer rays, reaching anal spines. Anal III 8; 
third spine as long as and stronger than longest dorsal spine. 
Caudal rounded. Caudal peduncle a little deeper than long. 
Scales cycloid, 30 4; lat. 1.5. Olive, with yellowish spots 
occupying the centres of the scales ; a rather indistinct dark 
lateral streak ; vertical fins blackish, with round yellow spots. 
Total length 175 millim. 
A single specimen. 
Synodontis pleurops. 
Premaxillary teeth in 6 transverse series; mandibular teeth 
17, uncinate, simple, measuring 4 diameter of eye, forming 
a small fascicle; no posterior villiform mandibular teeth. 
Depth of body equal to length of head, 4 times in total 
length. Head little longer than broad, flat on the crown; 
snout triangular, broader than long; eye perfectly lateral, just 
visible from below as well as from above, its diameter 13 in 
length of snout, 35 in length of head, 23 in interorbital 
width. Gill-cleft very narrow, not extending below base 
of pectoral. Maxillary barbels small, simple, hardly reaching 
base of pectoral; mandibular barbels fringed, outer twice as 
long as median and half as long as maxillaries. Dorsal IL 7 ; 
spine not serrated. Adipose fin small, 4 length of head, 
shorter than its distance from the dorsal. Humeral process 
simply granulate, obtusely pointed, not extending quite as 
far as the occipito-nuchal shield, which is 14 as long as 
broad and does not extend beyond the first soft ray of the 
dorsal. Anal IV 8. Caudal deeply bifurcate. Skin smooth. 
Brown above, whitish beneath; fins greyish white, with a 
blackish stripe along each lobe of the caudal. 
Total length 170 millim. 
A single specimen. 
Prof. L. Vaillant has recently published a monograph of 
this genus (Nouv. Arch. du Mus. (3) vil. & viii. 1895-96). 
Eight species are recorded by him from the Congo basin, 
and may be distinguished, together with the one now added, 
by means of the following synopsis :— 
