Male Genital Armature of the Derma/itera. Part II. 529 



eliminate from our mind any idea that the development or reduc- 

 tion of the organs of flight is of taxonomic value ; and secondly, 

 that even the presence or absence of the virga, a feature to which 

 Zacher, not unnaturally, attached great importance, has very great 

 value. There are, indeed, cases where it seems to have only specific 

 value, as, for instance, in the separation of Anisolabis pagana, 

 A. littorea, and A. verhoeji on the one hand, from A. maritima, 

 A. maurctanica, and A. kudagze on the other. 



The best way, so far as I can at present see, to divide the rest 

 of the Psalidse is according to the length of the metaparameres ; 

 this has, at all events, the merit of convenience, and the results do 

 not appear to be very unnatural. In the first group, the meta- 

 parameres are elongate, decidedly longer than broad, and therefore 



Fig. 58. — Anisolabis isomorpha Bor. 6 • Apex of abdomen (from a 

 specimen from the Cameroons, in the Berlin Museum). 



relatively narrow, often extremely so. In the second group, these 

 segments are of moderate length, from one-and-a-half to three 

 times as long as broad ; and, finally, the third group, in which 

 they are of about equal breadth and length. 



I have long since come to the conclusion that the presence of 

 chitinous pads, denticulate plates and so on, in the preputial sacks 

 has only specific value, and that such of Zacher's genera as are 

 based solely upon them cannot stand. 



For purposes of convenience, the tables of the genera of each 

 of these four groups is given separately. 



The West African species of Anisolabis are rather numerous, 

 and difficult to distinguish. 



A. turgida Burr, A. quxrens Burr, A. pagana Burr, and A. 

 silvestrii Bor., form a group with the abdomen very nearly smooth. 

 In A. owenii Burr, A. tumida Bor., A. isomorpha Bor. (fig. 58), and 

 A . incisa Bor., the punctulation of the abdomen is much stronger. 



