256 



J. M. DALZIEL. 



found; e.g., in 1917, an exceptionally wet year, there were 20 finds in 14 species, 

 and the total up to June 1919 includes 74 occasions in 27 different species. Kot- 

 holes in cut timber are not included, nor are the rotting stumps of banana plants, 

 which, when not rooted out, are a most prolific source of S. fasciata in native com- 

 pounds. Samples of larvae were procured in a majority of instances, and the 

 ioUowing six species of mosquitos were determined after hatching : — 



Table II. 



Species of Mosquito. 



No. of times found. 



Percentage. 



Stegomyia luteocephala. . 



„ fasciata 

 Guliciomyia nebulosa . . 

 Culex deccns 



Ochlerotatus apicoannulatus . . 

 Uranotaenia annulata . . 



33 



15 



Ij 

 54 



61 

 28 



11 



Apart from one or two exceptions from neighbouring villages within the municipal 

 area, the Lagos samples were all from the town proper, including the native town 

 and the area around the Race-course and Golf-course. The preponderance of 

 S. luteocephala is obvious in this fist and seems to be out of proportion when com- 

 pared with tree-bred species in the Gold Coast and Sierra Leone. Other 

 sources of this species in Lagos have been as follows : — Crab-hole (once only), a 

 pool, the metal socket of a telegraph pole, and roof -gutters (similarly in Accra). 

 In Freetown, Sierra Leone, its chief source was in hollows at the roots of the silk- 

 cotton tree {Eriodendron orientale), occasionally in rock-holes, rarely in domestic 

 utensils, and once in a coco-yam plant (Bacot — Report on Entomological 

 Investigation undertaken for the Yellow Fever (West Africa) Commission, Aug. 

 1914 to July 1915). 



The larvae of 0. apicoannulatus have not been found in Lagos (during the course of 

 these observations) except on the one occasion in a tree-hollow (a mango). In Free- 

 town, Bacot (loc. cit.) gives its sources as water-holes at the roots of Eriodendron 

 and also rock-pools and occasionally tins. In Accra they have been obtained 

 from a flamboyant tree in company with three species of Stegomyia (Ingram and 

 Macfie, Bull. Ent. Res. viii, p. 145). A curious find in a banyan tree was 

 S, luteocephala in a hole, and S. fasciata in a salmon tin lodged in the fork. In 

 another banyan three species were found, viz., S. luteocephala in excess, along 

 with S. fasciata and Culic. nebulosa. 



One species in the above list I do not remember having seen in records from 

 others places, viz., U. annulata, found once alone and abundant in an ornamental 

 screw-pine (Pandanus veitchii) at Government House. S. africana, along with 

 Ochlerotatus marshalli, has been found by Graham in a cut bamboo, and 

 0. longipalpis, Griinb. {S. pollinctor, Graham) in a hollow tree at Yaba (Bull. Ent. 

 Res. i, pp. 28-31\ 



