16 H. STEMPFFER 



shape ; thorax short and slender ; abdomen long, swollen in its apical portion ; legs short, 

 robust, bearing a few scales but no hairs, tarsi spinose ventrally ; $ fore leg with the tibia finely 

 spinose ventrally, tarsus short, unsegmented and ventrally spinose. 



Wing venation (Text-fig. 233). The cell is very long in both wings ; hind wing with a short 

 precostal vein at the base. 



Male genitalia (Text-figs 8, 9). The genitalia of the $ are asymmetric and highly specialized, 

 but very constant in form throughout the genus. In order to appreciate their configuration 

 thoroughly it is necessary to separate the dorsal and ventral portions and to arrange the parts 

 separately flat on a slide ; a preparation showing the parts in situ, in profile, is only confusing 

 and of no use for the recognition of specific characters. Uncus trifurcate, the median process 

 much the longest, the two lateral lobes asymmetric, curved inwards ; tegumen very large, 

 hood-shaped, also slightly asymmetric ; gnathos strongly chitinized and trumpet-shaped in 

 lateral aspect ; sternite prolonged towards the eight segment by two rounded expansions and 

 ending in an asymmetric feebly chitinized portion towards the apex of the abdomen ; there are 

 no true articulated valves but five asymmetric expansions of the vinculum, the shapes of which 

 provide excellent specific characters ; penis very long and cylindrical, slightly incurved towards 

 the apex ; the fully eversible vesica was found everted in all specimens examined, producing 

 the appearance of a flail. 



Female genitalia (Text-fig. 10). The $ genitalia are also very specialized. The anal papillae 

 are covered with fine silky hair and are devoid of posterior apophyses. The wide ostium bursae 

 opens on the seventh sternite and is easily visible to the naked eye, which enables the sex to be 

 recognized with ease. The ductus bursae is at first strongly chitinized, and the sclerotized por- 

 tion, which makes a swelling on the underside of the abdomen, takes an even curve that seems 

 to correspond with the curve of the terminal part of the penis ; the membranous portion of the 

 duct is folded back at an acute angle towards the apex of the abdomen. In this way one can 

 understand the peculiar situation imposed on the vesica at the time of copulation, a situation 

 which is retained after copulation and is found on dissecting the males. 



I have been able to examine the male genitalia of all known species of Pentila 

 except P. umbra Holland. As indicated above, they are all of the same general type 

 as tropicalis, yet they provide good specific characters. The genus, though numerous 

 in species, is perfectly homogeneous. 



Nothing is known of the early stages of any species, which is surprising, for many 

 of the species are abundant in their habitats and they are widely distributed 

 geographically. 



Fig. 10. Pentila tachyroides f. roidesta Suffert, $ genitalia. 



