682 MR. C. TATE REGAN ON THE 



1. PSEUDOTROPHEUS WILLIAMS! Guntl)., 1893. 



Chromis williamsi Glinth. P. Z. S. 1893, p. 624, pi. Ivi. fig. 0. 



Tilapia livingstonii Bouleng. P. Z.S. 1899, p. 134, pi. x. lig. 2; 

 Cat. Afr. Fish. iii. p. 243, fig. 162. 



Tilapia wiUiamsi Bouleng. Oat. Afr. Fish. iii. p. 225, fig. 147. 



Depth of body equal to length of head, 3 in length of fish. 

 Upper profile of head convex ; snout as long as or a little longer 

 than diameter of eye, which is 34 to 4 in length of head, nearly 

 equal to or greater than the interorbital width, depth of cheek, 

 or prseorbital. Mouth terminal, rounded ; maxillary extending to 

 below anterior edge of eye ; teeth in 5 or 6 series, inner small, 

 tricuspid ; 40 to 52 teeth in outer series of upper jaw, the last 



3 or 4 (young) or 6 to 9 (adult) on each side conical, enlarged 

 and sharply dirrerentia.ted from the rest, which are bicuspid. 



4 series of scales on cheek. 9 or 10 gill-rakers on lower part 

 of anterior arch. Pharyngeal teeth small, slender. 33 scales 

 in a longitudinal series, 6 from origin of dorsal to lateral line. 

 Dorsal XVI-XVIl 9 ; last spine a little less than | length of 

 head. Anal III 8 ; third spine a little shorter than dorsal. 

 Pectoral | length of head, not reaching anal. Caudal truncate?, 

 densely scaled in basal half. Caudal peduncle as long as or a 

 little longer than deep. Body with 6 dark cross-bars, or bars 

 represented by a series of spots above lateral line and another on 

 middle of side; an opercular s2:)ot and a dark bar or spot on base 

 of caudal ; two round white (? orange) spots on anal fin (pro- 

 bably absent in $ ). 



Two specimens, types of the species and of T. livinr/sionii, 105 

 and 75 mm. long. 



2. PsEUDOTROPHEUS ZEBRA Bouleng., 1899. 



Tilapia zebra Bouleng. Cat. Afr. Fish. iii. p. 244, fig. 163 (1915). 



Depth of body 2| in length, length of head 3i. Snout de- 

 curved, a little longer than diameter of eye, Avhich is 4 in length 

 of head, a little greater than depth of pra?orbital, equal to depth 

 of cheek; interorbital width 3 in length of head. Mouth ter- 

 minal, rounded, rather wide; javi^s equal anteriorly: maxillary 

 extending to vertical from anterior edge of eye ; teeth in 4 or 5 

 series. 56 in outer series of upper jaw, the last 8 or 9 conical. 



5 or 6 series of scales on cheek. 12 gill-rakers on lower part of 

 anterior arch. 31 scales in a longitudinal series, 8 from origin of 

 doi'sal to lateral line. Dorsal XVIII 9 ; last spine nearly | length 

 of head. Anal III 9 ; third spine a little shorter than last dorsal. 

 Pectoral neai'ly as long as head, not reaching anal. Caudal 

 proba^bly truncate, 'densely scaled at base. Caudal peduncle a 

 little deeper than long. A dark bar between eyes, a second from 

 opercular spot to occiput ; 6 vertical bars on body, the first from 

 origin of dorsal to base of pectoral, the sixth from soft dorsal to 

 anal ; three round pale (? orange) spots on anal in male. 



The type, 105 mm. in total length. 



