OF FISHES FROM LAKE TANGANYIKA. 21 
22, PERISSODUS MICROLEPIS, sp. n. (Plate VI. fig. 2.) 
10 teeth on each side of the premaxillary, 9 on each side of the mandible. Depth 
of body 3% times in total length, length of head 34. Snout a little longer than 
diameter of eye, which is 4 times in length of head, and almost equals interorbital 
width ; lower jaw projecting; maxillary extending to below anterior border of eye; 
3 series of scales on the cheek ; large scales on the opercle. Gill-rakers rather long, 
14 on lower part of anterior arch. Dorsal XVIII 10; spines increasing in length to 
the last, which measures ? length of head; longest soft rays 2 length of head. 
Pectoral 2 length of head. Ventral not reaching vent. Anal III 8; third spine 
longest, nearly as long as longest dorsal ; longest soft rays half length of head. Caudal 
truncate. Caudal peduncle 1% as long as deep. Scales 65 a; lat. 1. —— Uniform 
dark reddish brown; a blackish opercular spot. 
Total length 100 millim. 
A single specimen from Mbity Rocks '. 
1 T think it desirable to allude here briefly to two remarkable genera of Cichlide trom Lake Tanganyika, 
which I have founded on specimens obtained by Capt. Descamps and sent to me for study by the 
Administration of the Congo Free State. The specimens are in so bad a condition that it will never be 
possible to draw up from them complete definitions of the species, but their dentitions, which indicate 
remarkable new genera, are well preserved, and I am sure the annexed figures together with the short notes 
here given will be sufficient to ensure their future recognition :— 
Ecropvs, g. n.—Teeth very small, conical, in two series in both jaws, the outer larger; outer mandibular 
teeth pointing outward, perpendicular to the others; maxillary concealed under the przorbital when the 
mouth is closed. Scales rather large, ctenoid. Dorsal with 14 spines, anal with 3. 
Ectodus descampsi, sp. nu. (Fig. 1, a..—D. XIV 14; A. III 8. Depth of body 3% times in total length, 
length of head 3. Eye very large, 24 in length of head, 13 interorbital width. Two series of scales on the 
cheek. Sc. 34 2; lat.1. =. Total length 95 millim. 
Ectodus melanogenys, sp.n. (Fig. 1,4.)—D. XIV 16; A. III 13. Depth of body 5 times in total length, 
Fig. 1. 
Sat 
a. b. b. 
length of head 33, Eye 4 times in length of head, 12 in length of snout, 1j interorbital width. Three series 
of scales on the cheek. About 35 scalesin a longitudinal series. A black spot on the chin. Total length 
95 millim. 
