39 



high degree of salinity is not essential for this species, which is one of 

 the most troublesome mosquitos in houses. The larvae of 0. tritaenio- 

 rhynchus, Giles, occurred in large numbers in a swamp formed by the 

 heavy rains in June, where a day or two later the larvae of C. tigripes 

 var. fuscus were found preying upon them. A week later none were 

 to be found, but other natural enemies such as Ephemerid larvae, 

 dragon-fly larvae, Notonecta, larvae of Hydaticus and other water- 

 beetles were unusually numerous. C. guiarfi, Blanch., was found 

 breeding in a swamp on both sides of the railway embankment and 

 covered with Pistia straliotes ; Mimomyia spleiidens, Theo., bred in a 

 small pool covered with the same water-weed, with which its larvae 

 appear to be definitely associated. The leaves of this plant are strongly 

 ribbed on the under-surface, and in expanding come in contact with 

 the surface of the water carrying down with them a film of air. The 

 larvae attach themselves to the leaves in a horizontal position with 

 their siphons inserted into the air film, in which position they were 

 able to hve for as long as 24 hours and even moult, without direct 

 access to the air. 



ScHWETz (J.). The Western and Northern Limit of Glossina morsitans 

 in Northern Katanga. — Bull. Eniom. Research, London, viii, no. 2, 

 pp. 165-168, 1 map. 



A knowledge of the distribution of Glossina morsitans is of the 

 utmost importance, entomologically, medically and economically, 

 because of the obstacle to the breeding of cattle presented by this 

 carrier of animal trypanosomiasis. In a previous paper, the restriction 

 of this insect to regions with a particular type of vegetation was 

 suggested as the result of observations made between the rivers Lualaba 

 and Lomami in 1913 and 1914 [see this Review, Ser. B, iv, p. 30]. More 

 recent journeys over the same ground in 1916 have more definitely 

 determined the western limit and also estabUshed the northern limit 

 in the neighbourhood of 5°'30 S. Lat.. that is, a little south of Kongolo. 

 The western limit coincides roughly with the Lualaba-Lomami 

 watershed, but frequently this insect disappears a little to the east of 

 this line. It must be understood that the limit of G. morsitans is not a 

 precise, sharply defined or permanent line, but is affected by seasonal 

 variations, especially those due to bush fire migrations. 



ScHWETZ (J.). Preliminary Note on the Tsetse-flies of the Kabalo- 

 Albertville (Lualaba-Tanganyilca) Railway. — Bull. Entom. Research, 

 London, viii, no. 2, pp. 169-175, 1 map. 



Previous investigations of the route of the Lualaba-Tanganyika 

 Railway from the point of view of Glossina have already been noticed 

 [see this Review, Ser. B, i, p. 31]. The present notes made in 1916, 

 since the completion of the railway, establish the fact that G. morsitans 

 occurs in great numbers along the western third of the railroad and 

 along the eastern third rather less abundantly, but not at all, or hardly 

 at all along the intermediate portion, where however G. palpalis, 

 G. brevipalpis, G. palliddpes and G. fusca are all found. 



This distribution of G. viorsitans is due to the dift'erence of vegetation 

 in the three sections, and not to the presence or absence of game. The 



