OF FISHES FEOM LAKE TANGANYIKA. 19 



with the pharynx filled with embryos belongs to the female sex, while Dr. Lortet's 

 observations on T. simonis had led to the belief that specimens carrying eggs in that 

 manner are invariably males. 



It is here necessary to recall the observation contained in Livingstone's 'Last 

 Journals,' vol. ii. p. 17, that the " Dagala " or " Nsipe," of Lake Tanganyika, a small 

 fish 2 or 3 inches long, and very like Whitebait, is said to emit eggs by the mouth. 

 The comparison of this fish to Whitebait excludes the possibility of the one here 

 described being the " Dagala " or " Nsipe," which will probably prove to be a 

 Cyprinodont, if not actually the Haplochilus tanganicanus described below. 



SiMocriROMis, g. n. 



Body moderately elongate ; scales ctenoid. Jaws with broad bands of minute 

 tricuspid teeth, with an outer series of larger bicuspid teeth, and a single series of 

 conical teeth at the sides of the prsemaxillary ; maxillary concealed under the prse- 

 orbital. Dorsal with 17 or 18 spines, anal with 3. Vertebrae 31-32 (15+16-17). 



The type species differs from the other members of the genus to which it was 

 originally referred in the differentiation of the teeth at the sides of the prsemaxillary, 

 a character in which it agrees with the genus Tropheus. 



20. SlMOCHROMIS DIAGRAMMA Gthr. 



Chromis diagramma Gunth. Proc. Zool. Soc. 1893, p. 632, pi. lviii. fig. 3. 



The bands of teeth in both jaws consisting of 8 to 10 series, gradually decreasing in 

 size from the outer border. Depth of body 2 J to 2f times in total length, length of 

 head 3| to 3^. Snout descending in a strong curve ; diameter of eye 3 to o^ times in 

 length of head, 1^ in interorbital width ; mouth extending to below anterior border of 

 eye ; 4 series of scales on the cheek ; large scales on the opercle. Gill-rakers short, 

 12 or 13 on lower part of anterior arch. Dorsal XVII-XVI1I 9-10 ; spines increasing 

 in length to the sixth, which measures f- to -| length of head ; longest soft rays about § 

 length of head. Pectoral as long as head. Ventral reaching vent or origin of anal. 

 Anal III 7-8 ; third spine longest, as long as longest dorsal. Caudal truncate. Caudal 



peduncle as long as deep. Scales 31-33 j^; lat. 1. jy-j^;. Olive, whitish beneath; 

 young with 9 rather indistinct vertical bars ; gill-membrane sometimes with dark brown 

 spots ; fins greyish ; a dark brown stripe may be present along the spinous dorsal, 

 which has a black edge. 



Total length 105 millim. 



Four specimens from Kinyamkolo. 



d2 



