﻿148 JAS. J. SIMPSON — ENTOMOLOGICAL 



recorded since 1905 for any one year was at Calabar in that year, namely, 

 167*39 inches ; at Shaki in the extreme north-west only 17*85 inches fell 

 in 1908. 



As has already been pointed out, the coast-line of Southern Nigeria is very 

 irregular in shape, so that it is not possible in all cases to compare places in the 

 same latitude, but, generally speaking, stations on the same parallel of latitude 

 have similar rainfalls ; the table also serves to show that the rainfall diminishes 

 from the coast northwards, but not so markedly along the basins of the Niger 

 and Cross Rivers ; for example, Lagos 71*08 inches, Ibadan 50*65 inches, Oyo 

 43*00 inches, and at Shaki the mean for the two years (1907-8) during which 

 observations were recorded, 25*33 inches : or again Calabar 147*34 inches and 

 Afikpo 83*39 inches. Further examination, however, reveals the fact that these 

 means, though very diverse in magnitude, may be grouped according to definite 

 geographical areas thus : — 



(1) Calabar. The mean annual rainfall at this station, nearly 150 inches, is 

 the highest for the Colony. This station is situated on the Coast in what might 

 be termed the Cross River Delta, and further it is at the base of the Kamerun 

 Mountains. 



(2) Bonny, Forcados and Sapele. These three stations have a mean annual 

 rainfall of over 100 inches and may be topographically considered as lying 

 within the Niger delta. In this region it will be seen that the rainfall decreases 

 from the coast inland. 



(3) Afikpo and Bende. The mean annual rainfall in this area is about 80 inches. 

 Both these stations are in the Cross River system, but Afikpo, though further 

 north, has a slightly higher maximum owing to its closer proximity to the basin 

 of the river. 



(4) JEpe, Lagos, Badagri and Onitsha. Lagos, Epe and Badagri are all 

 situated along the coast in the Lagoon region, but Onitsha is on the Niger about 

 150 miles north of Forcados. Owing, however, to its being actually in the basin 

 of the Niger, its rainfall is greater than its inland situation would otherwise lead 

 one to expect. 



(5) Ibadan, Oshogbo and Oyo, These three stations may be grouped together 

 as representative of the hinterland of the Western Province, while a still further 

 reduction in the mean rainfall is seen in the case of Shaki, where in 1908 only 

 17*85 inches were recorded. Unfortunately, this region is comparatively 

 unknown, and, as no European is now stationed there, no further meteorological 

 observations are available. 



Generally speaking, therefore, the greatest rainfall is in the Eastern Province, 

 near the Kamerun Mountains ; it is slightly less in the delta of the Niger, while 

 along the Lagoon region and in the basins of the Niger and Cross Rivers there 

 is a still further decrease. The area with the least rainfall is the hinterland of 

 the Western Province. These facts are of some importance in a study of the 

 distribution of the various species of blood-sucking insects. 



