2 THE TANGANYIKA PROBLEM. 



about § length of head. Caudal rounded. Caudal peduncle deeper than long. 



3 22 — 23 



Scales 32-3<; — ; lat. 1 -^ — . Blackish brown, with scattered pale blue dots ; 



J JJ 11 — 12 6 — 9 



belly yellowish. 



Total length, 75 millim. 



Described from five specimens from Mbity Rocks and three from Kinyamkolo. 



The toothed portions of the prcemaxillary and mandible are much developed in 

 depth, in a manner suggestive of the Sparida and Scaridm, and the teeth are 

 implanted in sockets. The deep triangular groove for the reception of the prse- 

 maxillaries extends to between the orbits, and the occipital crest is prolonged to it ; 

 the parietal crests are produced on the frontals ; the pmeorbital is large, and the 

 chain of suborbitals very slender. The pharyngeal teeth have long, slender shafts 

 and conical brown cusps. The ribs are attached to the back of short transverse 

 processes ; all but the last one support epipleurals ; the last four prcecaudal vertebrae 

 have a hcemal bridge. 



82. Spathodus erythrodon. — Blgr. 1900. 



83. Perissodus microlepis. — Blgr. 1898. (Fig. p. 213. Lower.) 



Ten teeth on each side of the prsemaxillary, 9 on each side of the mandible. 

 Depth of body 2§ times in total length, length of head 3I. Snout a little longer than 

 diameter of eye, which is 4 times in length of head, and almost equals interor- 

 bital 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 increas- 

 ing in length to the last, which measures l| length of head; longest soft rays f 

 length of head. Pectoral | 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 — ; lat. I r . Uniform dark reddish brown ; a blackish opercular spot. 



20 30—31 



Total length, 100 millim. 

 Described from a single specimen from Mbity Rocks. 



84. Xenochromis hecqui. — Blgr. 1899. 



Three specimens from Usambura. Grows to a length of 270 millim. D. XVI.- 



XVII. io-ii ; A. III. 9-10; So. 64-67 - ; lat 1 53ZL? 



1 * 20 35—43 



85. Plecodus paradoxus. — Blgr. 1898. 



D. XIX. 14; Anal III. 12. Depth of body 4 times in total length, length of 

 head 4} times. Eye large, longer than snout, \ length of head, \\ interorlntal 

 width ; maxillary extending to below anterior third of eye ; 3 series of scales on 



6 50 



the cheek. Sc. 6"?. — ; lat. I — " 

 17 40 



Total length, 90 millim. 



