570 ME. G. A. BOULENGEE ON A COLLECTION 



the eye and on the gill-cover ; dorsal fin fringed with black. The vertebrae number 

 36 (14+22). 



64. Trematocaea niqrifeons, sp. n. (Plate XLI. fig. 1.) 



Depth of body 3^ times in total length, length of head 3 times. Snout with 

 curved upper profile, a little shorter than the eye, which is twice and | in length of 

 head and a little exceeds interorbital width ; mouth extending to below anterior fourth 

 of eye ; head naked, with large cavities as in the other species of the genus. Gill- 

 rakers long and slender, closely set, 20 or 21 on lower part of anterior arch. Dorsal X 

 11-12 ; spines feeble, increasing in length to the last, which measures f length of 

 head ; last soft rays a little shorter. Anal III 10 ; third spine as long as longest dorsal. 

 Pectoral acutely pointed, a little longer than the head. Ventral not reaching origin 

 of ana]. Caudal with deep crescentic notch. Caudal peduncle once and ^ as long 

 as deep. Scales 29-30 ; upper lateral line 7-8 ; lower lateral line absent. Yellow ; 

 a blackish bar across the interorbital region ; dorsal and anal fins with a blackish streak 

 near the edge, which is white. 



Total length 75 millim. 



Two specimens from Sumbu. Native name : Kilomo. 



This species is very closely allied to T. marginatum Blgr., from which it differs in 

 the longer and much more numerous gill-rakers. 



Dr. Pellagrin, in his Monograph of the CichlidEe, p. 331, has expressed his doubts as 

 to the distinctness of T. unimaculatum from T. marginatum. A renewed examination 

 of the specimens in the British Museum has convinced me that these doubts are not 

 justified. T. unimaculatum differs from T. marginatum in having a smaller eye, a 

 narrower interorbital space, a strikingly longer caudal peduncle, much stronger dorsal 

 and anal spines, more numerous gill-rakers (17 or 18 instead of 10 to 16), and fewer 

 soft rays in the anal fin (7 or 8 instead of 10). Considering that I have before me 

 three specimens of T. marginatum and ten of T. unimaculatum, I feel confident that 

 such differences, occurring in combination, cannot be merely individual ; and the fact 

 that the largest specimen of the former species measures 63 millimetres (without 

 caudal fin) and the smallest of the latter only 70, proves that they cannot be ascribed 

 to age, as suggested by Dr. Pellegrin. The specimens are sufficiently well preserved 

 to show that the second or lower lateral line is totally absent ; its representation on 

 Plate XVIII. fig. 3 of my third Report in these ' Transactions ' is an error of the artist 

 which I unfortunately overlooked. 



65. Tkopheus mookii Blgr. 



A single specimen from Sumbu. Native name : Kifuta. 



Dr. Cunnington describes its colour when fresh as : " Dark reddish-brown, with 



