498 Annals of the South African Museum. 



| length of postocular part of head ; eye large. 2f s times in length of 

 head, equals interorbital width ; least depth of preorbital equals -i 

 diameter of eye ; mouth nearly - width of head, reaching to below 

 anterior border of eye ; 2 series of scales on the cheek, depth of scaly 

 part | diameter of eye. Gill-rakers short, thick, 15 on lower part of 

 anterior arch. 



Dorsal xv 11 ; spines subequal from the 6th, last spine !|- length of 

 head ; soft rays a little longer than longest spines. Pectoral nearly as 

 long as head, reaching to vent. Ventral length of head, outer rays 

 slightly produced, reaching to vent. Anal iii 9, 3rd spine a little 

 shorter than longest dorsal spine. Caudal subtrimcate ; caudal 

 peduncle If as deep as long. Scales cycloid, 27^ ; lateral lines ], s ,. 



Colour (of preserved specimen) olive brown, light on belly, scales 

 with dark outer edge, indistinct dark cross-bars on body ; an indistinct 

 dark opercular spot ; a black spot at base of anterior rays of soft 

 dorsal and one or two whitish spots enclosed by dark streaks ; anal 

 dark at base with a light outer half ; caudal dark at base, light in 

 centre, a black outer ridge. 



One specimen, 48 mm. in length, from Mazoe River, Rhodesia (Mr. 

 G. Arnold). 



13. TlLAPIA SWIEERTUAE, 11. Sp. 



Teeth in 5 series, those of the outer row much stronger and separated 

 from the 4 irregular inner rows by a short interspace ; 60 teeth in 

 outer series on upper jaw. Depth of body 2^ times in total length 

 excluding caudal, length of head 3| times. Head elevated, the profile 

 making a bold curve, 1~ times as long as broad; snout obtuse, with 

 convex upper profile, as long as broad and equal to postocular part of 

 head; eye 5 T V times in length of head, -i interorbital width, ~ least 

 depth of preorbital ; mouth - Avidth of head, reaching scarcely to 

 vertical of anterior margin of eye, lips moderate ; 4 series of scales on 

 cheek, width of scaly part 1^ times diameter of eye. Gill-rakers short, 

 some of them bifid, 8 on lower part of anterior arch. 



Dorsal xvi 12 ; last spine longest, a little more than length of 

 head ; longest soft rays produced, a little longer than head. Pectoral 

 li times length of head, reaching to vent. Ventral reaching to vent. 

 Anal iii 10 ; 3rd spine a little shorter than longest dorsal spine. 

 Caudal truncate ; caudal peduncle 1 J times as deep as long. Scales 



cycloid, 30 ~f, lateral lines ff. 



Colour (of preserved specimen) reddish brown, lighter beneath, 



