826 REPORT OF THE HARVARD AFRICAN EXPEDITION 
anophelines from a medical point of view, it is certain that several other species 
are to be found in Liberia. The only other mosquito previously recorded from 
Liberia is Aédes aegypti (Linnaeus). My collection includes the following eighteen 
species: 
Megarhinus brevipalpis (Theobald). Aédes (Aédimorphus) tarsalis (Newstead). 
Eretmapodites inornatus Newstead. GC ulex (Culex) quinquefasciatus Say. 
i. chrysogaster Graham. “ consimilis Newstead. 
Armigeres argenteoventralis (Theobald). i pruina Theobald. 
Aédes (Stegom yia) aegypti (Linnaeus). e ‘“  decens Theobald. 
africanus (Theobald). ‘*  (Neoculex) rima Theobald. 
re - apicoargenteus (Theobald). Lutzia tigripes (Grandpré). 
Aédes (Banksinella) fuscinervis Edwards. Anopheles (My yzomyia) gambiae Giles. 
palpalis (Newstead). funestus Giles. 
In Liberia the mosquitoes most troublesome and dangerous to man are a few 
domestic or urban species, whose breeding places are almost entirely the result 
of human activities. In the primary rain forest, second-growth, swampy forest, 
or mangrove, away from the towns, one is but little annoyed by these insects. 
In the towns, however, one is bitten mostly by Aédes aegypti, Culex quinque- 
fasciatus, Anopheles gambiae, and A. funestus, all of which are important carriers 
of human diseases. At Monrovia, I found that even these mosquitoes were not 
particularly numerous nor annoying during July and November; at any rate, 
they were much less abundant than in many other tropical places I have visited. 
Dr. A. W. Sellards had a similar experience in March, so that apparently much 
the same conditions prevail throughout the year. An investigation of the town 
and its immediate surroundings disclosed relatively few breeding places, al- 
though no attempt had ever been made at controlling or eliminating them. Some 
of these breeding places, such as open ditches of stagnant water or empty cans 
near houses, could easily be dealt with. The most difficult to control, however, 
will be the large open wells, surrounded by vertical stone walls, that are found 
in almost every yard throughout the town. At Monrovia both anophelines and 
Aédes aegypti were breeding in them. Some of the other old towns of the West 
African coast have the same problem. Thus at Lagos J. M. Dalziel (1920, Bull. 
Ent. Res., XI, p. 259) found twelve species of mosquitoes breeding in the wells: 
51.3 per cent of the samples contained Aédes aegypti; 14.7 per cent, Culex 
decens; and 13.2 per cent, Anopheles gambiae. 
At present the wells furnish practically all the water used in Monrovia for 
cooking, drinking and other domestic purposes. As it would be impossible to 
suggest any other practical method of supplying the town with water, the re- 
moval of the wells is out of the question. It might be possible to close the top 
with concrete and to provide every well with a pump; but even this suggestion 
could probably not be carried out under existing conditions. In order to be 
effective, it should be applied to all the wells of the town. Perhaps the proper 
solution of the problem might be to stock the wells with certain small fishes that 
feed upon mosquito larvae. To be most successful, such attempts at control 
will probably have to use two types of fishes, v2z., surface feeders (such as species 
