Mr. R. Shelford's Studies of the Blattid^. 237 



lapponica, L. Supra-anal lamina shortly triangular ; ante-penulti- 

 mate segment with posterior border notched ; sub-genital lamina 

 produced, rounded, without styles, the sternum of the preceding 

 segment represented by two lateral lappets, the central part concealed 

 beneath the preceding sternum. 



Total length 13 mm. ; length of tegmina 11 mm. 



Gambia. One example (Oxford Museum). 



This species is remarkably like Ectobia Icqqyonica, L., the 

 resemblance extending to the wing structure ; the venation 

 of the tegmina is however sufficient to separate the species. 



The following table shows the differences between the 

 four known species of Theganopteryx from W. Africa : — 



1. Pronotum bordered with hyaline. 

 2. Tegmina not black. 



3. Tegmina with 20 to 22 costal 



veins, wing venation different 



from that of E. lapponica . . T. senegalensis, Sss. 



3'. Tegmina with 10 costal veins, 



wing venation exactly as in 



E. lapponica T. gambiensis, mihi. 



2'. Tegmina black T. sethiopica, Sss. 



r. Pronotum not bordered with hyaline . T. nitida, Borg. 



Blatta aiiuvna, Wlk., $, appears to be the same as T. scne- 

 galcnsis, Sss., but the female is a species of Tcmnoptcriix ; 

 a specimen from Natal under the same name in the British 

 Museum is a distinct species of Theganopteryx. I doubt 

 if Blatta fidvipes, Wlk., can be separated from Blatta 

 amcena, "Wlk,, $. 



Theganofteryx aithiopica, Sauss. 



The form of the " titillator " is shown in Plate XV, fig. 3, 

 it is almost identical in Th. senegalensis, Sauss. 



Genus Hemithyrsocera, Sss. 



This is not a satisfactory genus, unless it is restricted to 

 one species, histrio, Burm., which has plumose antennae in 

 both sexes, and exhibits a remarkable form of sub-genital 

 lamina in the male ; in the other species the antennge are 

 inconspicuously pilose in the male sex and not pilose in the 

 female, and there is really little to prevent the inclusion of 



