TEOM THE LAKE NGAMl BASIN, BECHUAN ALAND. 413 



dorsale d'un gris sale, avec les rayons et I'extremite de la partie membraneuse jaunes ; 

 I'anale grise, parseinee de points rouges, et ayant I'extremite jaune ; les ventrales d'un 

 vert obscur ; les pectorales de meme couleur, mais ayant leur extremite jaune ; iris 

 vert. — II y a 26 ecailles sur la portion superieure de la ligne dorsale, et 17 dents 

 fines et serrees, sur quatre rangees, a la partie anterieure de la machoire superieure. 

 " Ce poisson est connu des naturels sous le nom de ' Lekeguana.' " 

 The following description is taken from the specimens, 125 to 275 mm. long, 

 obtained by Mr. Woosnam : — 



Depth of body 2f to 3^ times in total length, length of head 2f to 3 times. Head 

 2 to 2 J times as long as broad, upper profile slightly convex or slightly concave ; 

 prsemaxillary process much shorter than the oral branch of the same bone, not 

 extending to between the eyes ; lower jaw projecting ; snout obtusely pointed, as long 

 as broad, shorter than postocular part of head ; eye 5 to 6 times in length of head, 

 equal to or a little less than interorbital or prseorbital width ; mouth extending 

 to below anterior border of eye ; teeth moderate, in 3 or 4 series, 24 (young) to 40 on 

 each side of upper jaw ; 7 or 8 series of scales on the cheek, the vertical diameter of 

 the scaly part 1^ to twice diameter of eye. Gill-rakers moderately long, rather 

 slender, some of the posterior usually bifid or trifid, 11 or 12 on lower part of anterior 

 arch. Dorsal XV-XVIII 13-16 ; spines increasing in length to the last, which is 

 ^ to f length of head ; longest soft ray -j to f length of head. Anal 111 10 ; third 

 spine longest, ^ length of head. Pectoral f to -| length of head, not reaching vertical 

 of origin of anal. Ventral not reaching beyond vent. Caudal rounded or subtruncate. 

 Caudal peduncle a little longer than deep. Scales feebly rugose, not or but feebly 



4-^5- 23-25 



denticulate, 39-41 j^r^; lat. 1. jTrig- 



A coloured sketch of one of the specimens (native name : Nchu) represents the 

 fish as dark olive above, orange under the head, yellow on the anterior part of the 

 belly, bluish on the posterior part, each scale with a reddish-brown spot at the base ; 

 dorsal and caudal dark olive, with round reddish-brown spots ; anal purplish grey, 

 edged with yellow and with round red spots ; pectoral and ventral dark olive ; iris 

 dark olive, with a yellow ring round the pupil. 



Other specimens (in spirit) show the dark lateial band characteristic of the types of 

 the species. 



Total length 120 to 280 mm. 



Chromys livingstonii Casteln. (p. 13) is regarded by that author as so similar to 

 Chr. ngamensis as to constitute probably only a colour-variety. It may therefore be 

 referred to the synonymy of P. thumhergi, with a query. 



" La forme est semblable, mais le milieu du corps est d'un tres beau jaune dore, sur 

 un fond grisatre ; I'extremite de chaque ecaille est rouge ; la dorsale, la caudale et 



