17. ORTHOPTERA. 



2. Blattodea 



by 

 R. SHELFORD. 



With 2 plates. 



The number of species of Blattodea previously recorded from the region 

 traversed by Dr. Yngye Sjostedt's expedition is quite insignificant. Gerst^cker 

 described in 1869 the collection of insects made by Baron C. C. von der Decken 

 in the Kilimandjaro district, but scarcely more than a dozen of these were cock- 

 roaches. A few species from Mombasa and adjacent localities on the East African 

 coast have been described from time to time by various authors, but in the absence 

 of really representative collections no general review of the East African Blattid 

 fauna has been possible, as in the case of South Africa, Abyssinia, Madagascar, the 

 Cameroons and Angola. This group of insects is usually much neglected by collec- 

 tors, but this reproach cannot be laid to Dr. Sjostedt's charge, for his collection is 

 a very considerable one, including fifty-one species — about 677 specimens — many of 

 which are represented by long series of individuals of both sexes; in fact the collec- 

 tion may be safely regarded as thoroughly representatiA^e of the region in which it was 

 made. The species are referable to 29 genera, four of which are new to science, and 

 of the 51 species, 26 or more than half, are new. In the following account of the 

 collection the species are enumerated and described, species recorded by other authors 

 from the same region — which may be conveniently defined as lying between the 

 equator and 5° S. and between the Z^^^ and 40*'^ parallels of longitude — are also 

 noted and finally an analysis of this Blattid fauna and its comparison with the cor- 

 responding faunas of other regions of Africa is attempted. 



