RESEARCH IN BRITISH WEST AFRICA. 



345 



come from ? ^¥hen we take into consideration the small number of horses which 

 are brought to this province annually, and the extremely short interval which 

 elapses before these show symptoms of trypanosomiasis and die, we must 

 conclude that, whatever be the carrier, the percentage infected must be large. 

 It seems hardly i^ossible that the infection could be carried, in the circumstances 

 quoted, from horse to horse, but if this be so the infected insect must remain 

 infective for a very long time. More probable, however, is the hypothesis that 

 the insects become infective from some other soui-ce, such as game, but as this 

 has been neither proved nor disproved it opens up a fruitful line of research. 



V. EECOEDS OF BLOOD-SUCKTNG INSECTS AND OTHER 

 ARTHROPODS FROM NORTHERN NIGERIA. 



The majority of the insects mentioned in the following list have already been 

 referred to in the preceding pages, but it might be well to tabulate these for the 

 sake of completeness. The table will also form a guide to any who may be 

 interested in this work and serve to show what species may be expected, but it 

 must be borne in mind that in all probability this list is very far from complete, 

 especially as regards the more northerly parts of the Protectorate. 



In the majority of the species the records are far too scanty to admit of any 

 discussion of their distribution, so that I propose to leave this over until more 

 data are forthcoming. I may also add that several new species from Northern 

 Nigeria await description and these have not been included in the following list. 



Order DIPTERA. 

 Family Culicidab. 

 Section Anophelina. 



Anopheles ivellcomei, Theo. 

 Myzomyia costalis, Loew. 



„ funesta, Giles. 



„ umhrosa, Theo. 



„ marshaUi, Theo. 



flavicosta, Edw. 



Aedomyia catasticta, Knab. 

 Banksinella luteolateralis, Theo. 

 Culcx decens, Theo. 



„ duitoni, Theo. 



„ fatigans, Wied. 



„ grahami, Theo. 



„ guiarti, Blanch. 



„ invidiosus, Theo. 



., quasigelkhis, Theo. 



„ tigripes, Gr. va.i. fusca, Theo. 

 univittat.us, Theo. 



Myzoriiynchus mauritkmus, Gr. 



„ paludis, Theo. 



Nyssorhynchus maculijpalpis, Giles. 



„ pliaroensis, Theo. 



„ squamosus, Theo. 



„ watsoni, Edw. 



Section Culicina. 



Trichorhynchiis (Cidiciomyla) nebulosus, 



Theo. 

 Liidlowia mimomyiaformis, Newst. 

 Mansoidoides uniformis, Theo. 

 Muckhis mucidtis, Theo. 

 Reedomyki, hiannulata, Theo. 

 Stegomyia africana, Theo. 



„ fasckhta, Theo. 



„ gebeleinensis, Theo. 



„ stigens, Theo. 

 laeniorhynclius cristatus, Theo. 

 Joxorhynchiles hrevipalpiis, Theo. 



E 2 



