GENERA OF AFRICAN LYCAENIDAE 269 



them all. The distribution of some of these, amongst the genera of the Lipteninae, 

 are indicated below : — 



(1) Uncus crescentic, more or less excised along its posterior margin, surrounding 

 a subtriangular tcgumen, to which it is connected by a weakly sclerotized membrane 

 which is translucent under the microscope : Cooksonia, Durbania, Euthecta, Larino- 

 poda, Liptena, Micropentila (in part), Argyrocheila, Teratoneura, Iridana, Deloneura, 

 Poultonia, Epitolina, Batelusia, Powellana, Neaveia, Phytala, Stempfferia, Epitola, 

 Aethiopana, Neoepitola and Hewitsonia, but an uncus of this type is not found in 

 Pseuderesia (s. str.), Citrinophila, Teriomima, Baliochila, Cnodontes, Eresinopsides, 

 Eresina, Toxochitona and Pseudoneaveia, or at least not in all the species included in 

 these genera. 



(2) Vinculum prolonged to form a more or less well developed saccus, which 

 extends candad, not cephalad as is the case in most Lycaenidae. The saccus in this 

 case is not an integral part of the vinculum, but is fused to it and is fairly easily 

 detached in the course of dissection ; it is large and triangular in Cooksonia, Dur- 

 bania, Argyrocheila, Deloneura and Poultonia ; more elongate in Liptena, Micro- 

 pentila, Batelusia, Powellana, Neaveia, Stempfferia, Phytala, Epitola, Aethiopana and 

 Hewitsonia ; sometimes disproportionate and with a spatulate apex, e.g. in some 

 species of Liptena and Micropentila ; or even absent in some genera, e.g. Citrino- 

 phila, Baliochila etc. 



(3) The penis varies very much in shape ; its external portion is gradually 

 tapered in Cooksonia, Durbania, some Liptena, some Micropentila, Teratoneura. 

 Iridana and Epitolina ; bifid in Larinopoda ; strongly S-shaped in Falcuna, 

 Argyrocheila, some Citrinophila and some Eresina ; provided with large dorsal 

 expansions in Deloneura, Poultonia, Batelusia and some species of Epitola and 

 Hewitsonia ; disproportionately long, slender, and curved in Toxochitona ; its 

 apical part circulate in several species of Micropentila. 



(4) Finally there is the remarkable structure in Baliochila and Eresinopsoides 

 bichroma Strand, that deserves mention. This consists of two processes with weakly 

 sclerotized bases which are fused to the tegumen, and to the dorsal side of the penis, 

 and bear either apical hooks or many stiff erect bristles along the whole of their 

 length. 



I have not succeeded in dividing the Liptenini (sensu Aurivillius) into homogeneous 

 subfamilies, each having a distinctive type of male genitalia. On the other hand, in 

 the present state of our knowledge, with the male genitalia of many species still not 

 examined, the erection of a large number of subfamilies as an alternative solution, 

 seems undesirable. I think that here we are dealing with many different lines of 

 descent, some of which are very ancient and, in the course of a long evolution, have 

 undergone a complete modification of their original external appearance. What can 

 have been the factors which caused some of these species to resemble, in wing colour 

 and markings, Eurema or other Pieridae ? This is not the place to start a discus- 

 sion on the causes and evolution of mimicry, but to note its existence. In the course 

 of evolution there may have been convergent lines of development, which tended 

 towards not only similarity of external appearances but even similarity of venation, 



