374 Aniialif of ihf Soiitli African Miii^enm. 



II D. Family LIBELLULIDAE. 



II Da. SuBi AMii.Y CORDFLINAE. 



As shown in the table (p. 338), it is not possible to give a short 

 definition of the two subfamilies of Libelliil idae without giving at 

 least one unisexual character (the angulate hind wings of male in 

 Cordulinae), and even this character is not universal, as it is wanting 

 in the rather important genus Hemicordulia (like Anax in the 

 Aeschninae, and also like Anax a highly specialised type). The only 

 bisexual character of Cordulinae, the temporal projection of the eyes, 

 is rather inconspicuous and also suffers excejjtious, since a few 

 Libelhdiiiae (of the group Urothemis) show similar projections. Other 

 characters of Cordulinae are also unisexual : semitrausparent narrow 

 lamellae at interior margin of tibiae in males (strictly proper to 

 Cordulinae if confronted with Libelhdinae alone, but present also 

 in CMorogompliinae) ; strongly developed and differentiated terminal 

 appendages in males (a character of only relative value, more for the 

 Cordulia- than for the 3facromia-lme of the subfamily) ; unbranched 

 hamuli in genitalia of male (regular for all the Cordulinae, but 

 existing also iu not a few Libellulinae) ; a pair of anterior hamuli 

 visibly developed, against the anterior lamina of same organs, seems 

 more characteristic for the Macromia-lme, though existing in rudiments 

 also iu the Cordulia-line. The bisexual character of predominant 

 metallic colours is a vei-y conspicuous one, though not fully dis- 

 tinctive : there are some Cordulinae with no metallic colours, and not 

 a few Libellulinae with highly metallic ground-colour or pattern. 

 With all these exceptions and restrictions the two sulifamilies are 

 well justified, and an expert will scarcely ever have a moments doubt 

 about the correct placing of any given specimen. 



Cordulinae are much less homogeneous than Libellulinae ; evidently 

 some very ancient developmental lines have lieen retained and exist 

 in a few, now isolated, representatives. Various attempts to a rational 

 classification have been recently made ; the best of them (according to 

 the writer's opinion) is by Mr. E. B. Williamson. Without regard 

 to minor and partly intermediate groups two main branches may be 

 distinguished : the Macromia-\me with Aeschnid (more especially 

 Chlorogomphine) affinities in general build and also to some extent in 

 venatioual characters, and the Cordulia-\me which approaches 

 Libellulinae in both these characters. 



Iu Africa only the Macromia-\me is fairly represented, and only a 

 few members of this line are met with iu our present faunal limits. 



