The Odomitn or Dragrmflies of South Africa. 335 



b. (Heterochroniatic form.) Light coloui' on thorax and head bright 

 orange in immature sjiecimeus, shading to dull orange, lirownish or 

 olivaceous in fully mature specimens. Light colour e.xtended on head, 

 thorax and base of abdomen ; postocular spots large, cuneiform, united 

 to pale colour of occiput ; prothorax only with a narrow nnd-dorsal 

 black l)and. Segment 1 entii-ely pale ; 2 with a narrow terminal ring 

 and small terminal dorsal spot bi'onzy lilack. On the other hand, the 

 eighth alidominal segment is not of the light colour in this form, Tjut 

 bronzy lilack dorsally, like the preceding and following segments. 



Hind lobe of prothorax in both forms similar to male, but narrower 

 aud less distinctly trilobed. 



c?, Ahd. 23, hdw. 15 mm. ? , 24, 17. 



This species is known from Afi'ica, the islands of the Indian Ocean, 

 tropical and sub-tropical Asia in continental and insular distribution, 

 common in coast districts, perhaps frequenting brackish waters, and 

 consequently omnipresent in collections, be they ever so scanty, brought 

 from those vast regions. The relatively small number of senegalensis 

 in our South African collections is rather surprising, and may indicate 

 that at least the temperate parts of the region are beyond the limits 

 of the best conditions for its existence. I. senegcdensU is the only 

 Ischnura known from Africa south of the desert belt. It seems to be 

 common in Eygpt (Cairo, the Pyramids, etc.), and the only Ischnura 

 yet found there ; but it is not yet recorded from Algeria, Tunisia or 

 Tripolitania, where three other (Mediterranean) species of the genus 

 occur. 



AGRIOCNEMIS (St'lys, 1877). 



A genus known from the inter-tropical parts of the Old World. The 

 species are probably rather numerous, l)ut very imperfectly known. 

 The analogies (and probably affinities) of Agriocnemis and Ischmora 

 are striking in colour system as well as in some physiological features. 



Some of the Agriocnemis species are, in spite of their dwarfed 

 stature and exceedingly fragile frame, found over immense areas 

 (pygmaea aud feiniua). Agriocnemis contains the smallest known 

 species of Odonata. 



Agriocnemis exilis (Sclys, 1872 ; Sjijstedt, 1909). 



Mus. Hamburg : 2 J , 6 ? , Beira (22 . ix . 1911. W. Michaelseu). 



(J. Occiput and labium whitish. Labrum brilliant metallic green. 

 Genae, mandibles and a narrow transverse liand in front of antennae 

 light green. Dorsal surface of head otherwise bronzy black ; very 



