180 JAS. J. SIMPSON — ENTOMOLOGICAL 



there one sees small fishing villages, but beyond this town the whole area is 

 under water at high tide in the rains, and the only signs of human habitation are 

 a few fishing huts used during the dry season. Near Bonthe this creek is 

 divided in two by Sherbro Island and opens into the sea east and west of this 

 island. G. palpalis is everywhere abundant along the creek and Tab anus 

 fasciatns and T. besti var. arbucklei are far from uncommon ; T. postacutus was 

 also found near Yorke. 



Bonthe, as has already been stated, is an important port for ocean-going 

 cargo steamers. It stands on Sherbro Island, is well protected from the sea, and 

 is surrounded by mangrove swamp. A great amount of reclamation has been 

 done and work of a sanitary nature is being constantly pushed forward. Clearing 

 and effective sanitary measures have done much in recent years to diminish the 

 number of Glossina. palpalis which formerly must have swarmed over the whole 

 area. The two most troublesome mosquitos are Anopheles costalis and Stegomyia 

 fasciata, but according to Dr. Orpen, who was stationed there during my visit, 

 these have also been greatly reduced in numbers in the last few years. 



The journey from Bonthe to Subu was accomplished in rowing boats along the 

 lagoon which separates Turner's Peninsula from the mainland. Owing to the 

 large amount of fresh water which is constantly being poured into the lagoon by 

 the Bum River, the water is brackish only for a very short distance from Bonthe, 

 and consequently the mangrove area is very limited in this direction. This is 

 gradually replaced by grass, palms, and generally shrubby vegetation. The 

 shores are very low-lying and swampy (Plate XX, fig. 1). Glossina. palpalis was 

 caught at several places between Bonthe and Muchaj, and at the latter place 

 Anopheles costalis and Mansonioides uniformis were troublesome. 



Between Muchaj and Kattin the shores are again low-lying and swampy and 

 are covered for the most part with grass, but here and there clusters of oil palms 

 and bush are to be seen. G. palpalis was caught at Bap and Kattin and probably 

 occurs in many more places in this reach. Tabanus fasciatns and T. taeniola were 

 also found at Kattin, while in the bush behind this town Anopheles mauritianus 

 occurred in numbers. Between Kattin and Subu there are many small villages 

 which are high and dry during the dry season, but which are almost completely 

 submerged in the rains (Plate XX, fig. 2) ; miles of grass land are similarly under 

 water in the rainy season. The town of Subu is situated on Turner's Peninsula 

 to the south-east of the mouth of the Bum or Sewa River. G. palpalis was 

 obtained there and T. fasciatns was caught at several places between Kattin and 

 Subu. 



The town of Mafwe stands on the Bum River, about 50 miles from its mouth ; 

 to this point the writer ascended in a rowing boat. The banks on the lower part 

 of the river as far up as Torma are similar to those in the lagoon and are covered 

 with grass, with occasional stretches of overhanging bush. Near Gori the grass 

 diminishes in amount and is eventually replaced by tall overhanging trees and 

 dense undergrowth (Plate XXII, fig. 1). It may be taken as a fair guide to the 

 distribution of Glossina palpalis in this region if one says that wherever bush 

 occurs there that species will be found, but seldom, or never, where grass 

 predominates. The same may said of Tabanus fasciatns, 



