SIMOCHEOMIS. 



275 



and transverse when closed ; maxillary concealed under the praeorbital. 

 Dorsal with 17-19 spines, anal with 3. Vertebrse 32 (15-1-17). 



Intermediate between Tilapia and Tropheus. As pointed out by 

 Pellegrin, this genus is connected with Tilapia through T. wilUamsii. 



1. SIMOCHROMIS DIAGRAMMA. 



Chrom'is diagnimina^ Giiiith. Proc, Zool. Soc. 1893, p. 632, pi. Iviii. fig. 3. 

 Sbnochromls diaglramma, Bouleng. Tr. Zool. Soc. xv. 1898, p. 19, and Poiss. Bass. 



Congo, p. 451 (1901) ; Pellegr. Mem. Soc. Zool. France, xvi. 1901, p. 307 ; 



Boiileng. Tr. Zool. Soc. xvii. 1906, p. 571. 



Depth of body 2\ to o times in total length, length of head 3^ to '6h 



Fig. 187. 



tSiDwchrumis diagrainma. 

 Pembe. f. 



times. Head massive, rounded, not twice as long as broad ; snout 

 broader than long, with convex upper profile ; eye 3 to 3J times in 

 length of head, about 1^ times in interorbital width ; mouth with thick 

 upper lip, extending to below anterior border of eye or not quite so far ; 

 8 to 10 series of teelh in each jaw ; 4 series of scales on the cheek. 

 Gill-rakers short, 12 or 13 on lower part of anterior arch. Dorsal 

 XVII-XIX 9-10 ; spines increasing in length to the sixth or seventh, 

 M-hich measures | to J length of head ; longest soft rays about § length 

 of head. Anal III 7-9; third spine as long as and stronger than 



