The Odonata or 



of South Africa. 



253 



interruption of flight, The thoracic sutures, as given in our Text- 

 figs. 4 and 5, show clearly the homologies of the parts. In the 

 Zygoptera all the sutures drawn in Text-fig. 4 ai-e visible in many 

 cases, though there are genera and groups where the first lateral 

 suture is obliterated, at least in its upper half. In the Anisoptera 

 this suture disappears regularly upward from a level which corre- 

 sponds approximately to the metastigma ; but the homology of parts 

 is not seldom still visible in the disposition of the colours and 



FIG. 4. Phaon iridipennis. Lateral view of thorax, proth. Prothorax. 

 Ip. Posterior lobe of prothorax. ex. Coxa. tr. Trochanter. fern. 

 Femur, mesepist. Mesepisterrmm. mesepim. Mesepimeron. metepist. 

 Metepisternum. metepim. Metepiineron. msiepist. Mesinfraepisternum. 

 mtiepist. Metinfraepisternum. is. Median suture. Us. Humeral 

 suture. Us., 2ls. First and second lateral sutures, mss. Mesostigma. 

 mts. Metastigma. acts. Antealar sinus, fw. Forewing. hw. Hindwing. 



pattern. There are two pairs of respiratory stigmata on the thorax : 

 the mesostigrna is in a concealed position in the joint between the pro- 

 and mesothorax, and the metastigma is comparatively large and a 

 leading feature in the structure and pattern of the thoracic side. 



The feet are slender, though comparatively strong, spiny, with 

 various adaptations of their armature, according to systematic 

 position and sex. The coxae are free, relatively small, the trochanters 

 double ; the femora and tibise of about equal length ; the tarsi short, 

 three-jointed ; the claws mostly with a tooth on their ventral edge. 



The wings bear neither hair nor scales, only some minute, almost 



