718 DR. A. GUSTHEll ON FISUES [June 6, 



appearance of large spots ; the foremost of these spots is the 

 one on the operculum. A series of black spots along the base 

 of the dorsal fiu, each spot covering the base of a spine ; another 

 less complete submarginal series. 



One specimen, 130 millim. long, from the Kotchwah Eiver. 



This species is closely allied to the one which 1 have identified 

 (with doubt) with Hemichromis scJiwehischi, Sauvage (Ann. & Mag. 

 N.H. 1896, xvii. p. 273), and which Mr. Bouleuger — after com- 

 parison with the type of the latter — declares to be distinct, 

 describing and figuring it under the name Chromidotilapia kings- 

 lei/ce, P. Z. S. 1898, p. 151, pi. xix. fig. 2. Some of the front 

 teeth of the Kotchwah specimen are bent inwards, though not 

 quite so conspicuously as in the larger of the specimens of 

 Chromidotilapia (96. 5. 5. 38) ; but I cannot attach any value to this 

 supposed generic character, as a younger specimen of Chromido- 

 tilapia kingslei/ce (119 millim. long ; 96. 5. 5. 36) has the teeth much 

 less strongly bent than the older one. 



Chetsichthts. 



Chrysichthys, Octonematichthys, Melanodactylus, Bleeker (1858). 



Chrysichthys Giinther (1864). 



Mr. Walker's collection contained a number of specimens of this 

 genus, which eA^dently belouged to se\eral species. In order to 

 name them, aud to compare them with others from previous 

 collections with the determination of which I did not feel satisfied, 

 I have been led to revise the whole of the material which I had 

 brought together for the British Museum collection. The 

 following notes on the several species are the results of this 

 examination. 



I paid special attention to the disposition of the teeth on the 

 palate, and I convinced myself that I was right (Cat. Fish. v. p. 70) 

 in declining to use modifications, which in some of the species are 

 subject to individual variation, for the establishment of genera, as 

 has been done by Bleeker. I have also questioned the propriety 

 of separating Clarot€.i from Chrysichthys, statingmy reasons (pp. 71, 

 73), which, however, weighed so little with that ichthyologist that 

 he placed these genera in the ' Atlas Ichthyologique ' into two dis- 

 tinct groups, separated by forms like Boras, Syuodontis, &c. 



Chrysichthys aueattjs (Geoffr.). 



Chrysichthys auratus Giinth. Cat. Fish. v. p. 71. 



I refer, for the present, to this species a young specimen, 150 

 millim. long, from the Eiver Prah, as well as several still younger 

 ones from the Eiver Oftim. The eye of these young specimens is, 

 of course, larger than in an adult example from the Nile, the only 

 one I have for comparison. Also the skin on the upper surface of 

 the head is much less thick, which, agaiu, may be accounted for by 

 the difference in age. On the other hand, there are many 



