134 w. M. GRAHAM—RESULTS OBTAINED FROM A MONTHLY EXAMINATION 
At Lagos this species was found in the following Sanitary Divisions and 
Districts of the township :— 
Division <A #2 Districts C., E., Q., 8. 
* B des 55 K., oC 
” C nD 5 H, 
ie D ie $5 Hk, MoM 
It may be noted that these Districts are mostly situated on that edge of the 
island having the lowest elevation above sea-level. 
OTHER LARVA, 
Chironomus (33 species). 
Species of this genus were present in 23°9 per cent. of the total water- 
receptacles. These larve (“blood worms”) are commonly found in pots and 
barrels, and even in the large covered iron tanks used to collect rain-water from 
the roof. 
Psychoda (2 species). 
Species of this genus were present in 6°1 per cent. of the receptacles. The 
water in which they were found was usually extremely foul and often contained 
sewage. 
Drosophila (1 species). 
This species occurred in 1:0 per cent. of the receptacles examined, and a few 
of the pup were reared for identification purposes. 
Ephemeride. 
Larve were found in only 2 out of 1,043 receptacles examined, 
CRUSTACEA, 
Cyclops simillimus, Brady. 
This species was present in an average of 24°5 per cent. of all the water 
receptacles examined. The fact is of considerable importance in relation to the 
transmission of Guinea Worm, for natives frequently wash their feet in such 
vessels, and if suffering from Guinea Worm would, during such ablutions, infect 
any Cyclops present. Apparently therefore it is not necessary to go to water- 
holes or public wells to find a source of Guinea Worm infection. 
This species of Cyclops was originally found by me in the Gold Coast, 
where it was common in the borrow-pits along the railway. In Freetown Guinea 
Worm is a rare disease, while at Accra it is a common one. It would therefore 
be interesting to compare the distribution of this Cyclops in the two towns. 
