The Odonatn or Dragonflies of Soufh Africa. 397 



guiiieense and Ahhoiti are sometimes uot easily distinguished : as a 

 rule chrysostiyma is the largest of the three, has almost regularly two 

 rows Rs-Rspl at least for a few cells' length, has the pterostigma 

 smallest and lateral black bauds on abdomeu reduced, often inter- 

 rupted ; in mature colour aud good condition the mesepimeral whitish 

 stripe is a fairly constant character also for the female of rJirysostlgnia 

 (Text-fig. 71). 



This species, first descrilied from the Canary Islands, is found 

 throughout the African Continent from Ak'eria to Natal, also in the 



Fig. 71. — Orthetntm chrysosligmn, ^. Barherton. lienitalia, second 

 segment, left side view. 



extreme south of Europe and in part of Mediterranean Asia. There 

 is no other than individual variability recognisable. When working 

 out Orthefrum for the LibelluUnae monograph, the writer supposed 

 the two following forms to be geographical sub-species of chrijsostigma; 

 but more extensive materials and more careful study of the matter 

 made this view untenable, and a new arrangement (like the one given 

 hei'e) is adopted for the additions to the monograph. 



Orthetrum Abbotti (Calvert, 181)2). 



S. Afr. Mus. : 3 cJ . 3 9 , aud 2 cJ ? , in cop.. M'Fongosi. Zululand 

 (ii. iii . 1912, W. E. Jones). Brit. Mus. : 1 ? , Willow Grange, Mooi 



Fig. 72. — Oi-thetnim abbotti, $. M'Fongosi. Genitalia, second segment, 

 left side view. 



River, Natal (9 . ii . 1913, R. C. Wroughton). Coll. Ris : 1 ^, 

 Botchabelo, 12U0 m., Transvaal (23 . ii . 1914, H. Juuod). 



Extremely similar to following species in abdominal pattern, large, 

 bright yellowish pterostigma and general outline ; but different by 



