The Odonata or Dragonflies of South Africa. 247 



The question then arose whether an extensive enumeration of 

 synonymy and bibliography should be added to the descriptive part ; 

 the addition would not have been difficult, because the writer has at 

 his disposal a very detailed manuscript catalogue of all described 

 recent Odonata. But after mature reflection it Avas found that for 

 the present paper and its special purpose this would be of no practical 

 value. It would have been a repetition of a great amount of material 

 already published, some of it quite recently. To the reader interested 

 in this side of the study it may be said that (1) the sources of the 

 original descriptions can be easily traced by the aid of Kirby's well- 

 known and indispensable catalogue ; (2) as to the additions up to 

 1907, all bibliographical notes interesting South Africa have been 

 collected and published in the writer's catalogue for L. Schultze's 

 voyage, mentioned at the beginning of this introduction and published 

 in 1908 ; (3) for the entii'e subfamily Libellulinae the writer's mono- 

 graph of this subfamily gives a very detailed and, as far as possible, 

 complete bibliography ; it would have been tedious and useless to 

 repeat this here. For these reasons the synonomy and bibliography 

 are abandoned, and the quotations limited to the author's name and 

 the year of publication of each specific and generic name. The writer 

 wishes to indicate hei'e his opinion regarding authors' names in 

 zoological nomenclature. Authors' names should not be considered 

 as part of the animal's name, as is largely accepted, but simply as 

 a citation in a conventionally abridged form. Under this view any 

 author is free to extend the citation to other details besides the name 

 of the first describer, such as the year of publication ; and no doubt 

 this has a certain historical interest, giving as it does an abridged 

 sketch of the chronological development of knowledge. The ideal 

 would be, according to the writer, to abandon authors 1 names altogether, 

 and for a group or a fauna sufficiently known to a broader public, or 

 for a paper specially intended for those already initiated, this may be 

 perfectly admissible even in the actual state of knowledge. But it 

 would not have been advisable to have followed this method for this 

 paper, which aims to be an introduction to an insufficiently known and 

 as yet very imperfectly studied fauna. 



1. INTRODUCTION AND TERMINOLOGY. 



Dragonflies have retained the essential parts and segmentation of 

 a primitive insect or Hexapod through a long series of geological 

 periods. Far back in the Mesozoic age they were essentially what 

 they are now, and the systematic groups of the present time are 



