MOSQUITO LARVA IN SOUTHERN NIGERIA. 139 
introduction of Haplochilus grahami would be successful. They might also 
be tried in domestic water-barrels and tanks, if means were devised to prevent 
them from leaping out on to the ground. 
The following is a description of the colouring of the species, based on living 
specimens : 
Haplochilus grahami, Blgr. 
Colour, yellowish, with blackish brown markings upon the body. The fins are 
semi-transparent, and in the males especially, of a brilliant greenish yellow colour. 
In front of the base of the anal fin there is a large dark spot, from which 6 longi- 
tudinal lines, formed of smaller spots, run forward to the head. Six dark, 
transverse, almost equi-distant bands extend from back to belly, and there is an 
ill-defined large dark spot behind the eye. On the caudal fin, towards the base, 
are 3 to 4 transverse rows of dark spots, and the apex of the fin is drawn out into 
an irregular point or points. In both sexes the occiput is flattened, and bears a 
nearly circular spot of burnished silver. This spot is not luminous at night. 
The females are larger and less brilliantly coloured than the males. The 
markings are less distinct, the silver spot on the occiput has a rubbed 
appearance, and the fins are not so bright a yellow. Length, 18 to 40 mm. 
I have to thank Mr. G. A. Boulenger, of the British Museum, for identifying 
my specimens. 
The accompanying photograph was taken on a colour-sensitive plate through 
a yellow screen, and represents a magnification of two diameters. 
London, 31st May, 1911. 
