150 



In the Bonthe district the following blood-sucking Diptera were 

 captured : — Uranotaenia amiulata, Theo. ; Culex insignis, Cart. ; 

 C. decens, Theo. ; C. tigripes, Grp. ; C. consimilis, Newst. ; C. duttoni, 

 Theo. ; Culiciomyia nebidosa, Theo. ; C. freetoivnensis, Theo. ; 

 Mansoiiioides uniforniis, Theo. ; Taeniorhynchvs amiettii, Theo. ; 

 Ochlerotatus nigrocephalus, Theo. ; 0. caliginosus, Graham ; Glossina 

 palpalis, R. D. ; Tabanus fasciatus, F. ; T. congoensis, Ric. ; 

 T. obsairissimus, Ric. ; Hippobosca sp. ; PJdebotomus duboscqi, N.L., 

 and Culicoides sp. 



Larvae of the following mosquitos were found in crab-holes, at the 

 roots of trees, etc. : — U. anmdata, C. decens, C. tigrijies, C. duttoni, 

 C. freetoivnensis, 0. nigrocejjhalus, Anopheles costcdis and A, fimestus. 



Dalziel (J, M.) & Johnson (W. B.). Report on Yellow Fever Investi- 

 gation in Freetown. September 1913 to March 1914. — Yelloiv Fever 

 Bur. Bull., Liverpool, Supplement ii, August 1915, pp. 541-579, 

 8 tables, 1 chart. [Received 11th July 1916.] 



Investigations into the presence of yellow fever in Freetown were 

 based on the assumption that Paraplasma flavigenum is the virus of 

 the fever and can be demonstrated in the blood of fever patients. One 

 case of yellow fever in a European was definitely diagnosed, while 

 several others were found on suspected ships. Malaria was present 

 in 48 per cent, of the cases examined. 



Rats were found to be infected with the fleas, Xenopsylla cheopis, 

 Roths., and X. brasilicnsis, Baker. The louse, Polyplax spimdosus, 

 Burm., and a Gamasid mite, Laelaps sp. near echidninus, Berl., were 

 less common. Trypanosomes of the T. leivisi tvpe were present in the 

 blood of 60 per cent, of the rats examined. Stray dogs were attacked 

 by the flea, Ctenocephalus canis, Curt., and by the ticks, Rhipicephalus 

 sanguineus, Latr., R. simus, Koch, and a larval Amblyomma. 



During March, larvae of the folloAving mosquitos were collected in 

 the town : — Culex decens, Theo. ; C. duttoni, Newst. ; C. tigripes, 

 Grp. ; Stegoniyiafasciata, F. ; Anopheles costalis, Theo. ; Culiciomyia 

 nebulosa, Theo. S. fasciata formed 14 or 15 per cent, of the total 

 number of larvae. Adult mosquitos included S. fasciata, C. nebulosa 

 and rarely A. costalis. 



Chnical investigations during this period tend to show that yellow 

 fever no longer maintains an endemic persistence in Freetown. As yet 

 no endemic focus in Sierra Leone has been demonstrated ; it is possible 

 that no particular sea-port may be involved, but rather that the focus 

 may be found in the holds of merchant ships. Inspection of ships for 

 the presence of Stegomyia is to be undertaken. 



Fowler (Sir J. K.), Simpson (W. J.), Ross (Sir R.), Leishman 

 (Sir W. B.) & Balfour (A.). Third Report of the Yellow Fever 

 Commission (West Africa). — London, 1915, 51 pp. [Received 10th 

 July 1916.] 



This report summarises the main facts at present known concerning 



the virus of yellow fever. It is undoubtedly transmitted by Stegomyia 



fasciata, and it is not known to be carried by any other agent under 



normal conditions. The period required for its development in the 



mosquito is approximately 12 days. The blood of a yellow fever 



