loG 



[July, 



lengthened segment. Anotlier example had the termi-ial joint missing, 

 the third short and thickened, and the fourth much elongated and 

 slightly thickened {Douglas). The foundation for these defects must, 

 of course, have been laid during larval life. Now, as oligomery is most 

 common amongst the Lygaeidae, most of which spend their life upon 

 the ground, it seems as though there may be some connection between 

 this kind of teratology and the habit of living on the ground, amongst 

 the roots of plants, where the risks of damage to the antennae must be 

 considerable ; and the question naturally suggests itself whether the winter 

 retirement of larval P. rvfipes, presumably on the ground, under plants, 

 stones, etc., may be similarly responsible for tlie appearance of oligomery 

 in a Pentatomid, 



P. rufii^es shows no hesitation in the use of its wmgs, and readily 

 takes flight, and this may have something to do with the wide area it has 

 covered. In the British Isles it is probably quite general in distri- 

 bution : it has been definitely recorded from 30 English and 3 Welsh 

 counties, and it occurs in both Scotland and Ireland. Seven other 

 Palaearctic species of the same genus have been described, and these are 

 almost all Asiatic in distribution, and still others are found in other 

 l)arts of the world. 



35 Kyrle Road, 



Clapham Common. 

 May 20th, 1922. 



OBSERVATIONS ON THE PHYLLODROMINE COCKROACH, 

 BLATTELLA SUPELLECTILIUM Serv., IN KHARTOUM. 



BY K. COTTAM, 



Entomological Laboratory Assistant, Wellcome Tropical Research Laboratories, 



Khartoum, Sudan. 



In this paper certain habits of this cockroach are described, and an 

 account is given of its breeding habits, oviposition, and development as 

 observed in a series of experiments carried out at Khartoum in 1915. 



This small cockroach is one of the commonest species in Khartoum, 

 and is found in nearly all buildings and in native huts (tukls). It is 

 nocturnal, but may sometimes be seen moving about during the daytime. 

 Whilst searching for other insects, I have often disturbed it from holes 

 both on the river bank and in gardens. The wings are well developed in 

 both sexes ; but, though I have frequently seen this insect flying round 



