82 CLAUDE FULLER. 



but is generally well-developed, fig's. 182, 187; as a rule it 

 arises from the cubital, but has been found occupying an 

 independent position on the cardinal as shown in fig. 187. In 

 all cases, when present, the anal trachea is directed away from 

 the wing-sac into the thoracic cavity. The basal attachment 

 of the post-costal is most erratic. It may spring from the 

 radial, figs. 184,185; it may be independent (as in Rhino- 

 term es), fig. 182, but more often it arises from the stock of an 

 arborescent bunch of tracheas anterior to the union of the 

 cephalic arm of the leg-trachea with the cardinal, figs. 183, 186, 

 187. The radial usually stands independent upon the cardinal, 

 but has twice been found close to, fig. 185, or arising from, 

 fig. 183, the stock of the cubital. In but one nymph has 

 anything approaching the development of a medial trachea 

 been observed, fig. 187. In any one nymph of T.natalensis 

 four differing conditions may be found as regards the basal 

 connections of the trachese of the four wing-sacs. 



With reference to the post-costal trachea it may be added 

 that it is readily observed lying within the large outer 

 shoulder-like ridge of the wing-stump of the adult, should 

 the insect be fresh and not too long fledged. 



IXg. MiCROTERMES INCBRTDS [HttV.). 



Plate XI, figs. 188-200. 



The wings of this insect have the same structure as those of 

 Termes natalensis, etc., but display less regularity. The 

 main point of difference is that there is no inner branch to the 

 radius iu ninety-eight out of every hundred wings. Compare 

 fig. 190 with others. Occasionally, the radius and costa are 

 linked together by small struts, reminding one of those 

 common to the Rhinotermes wing, but each is obviously an 

 isthmus arising during chitinisation, figs. 188, 189, 193. The 

 irregularity that is most noticeable is due to the rare presence 

 of a true media, figs. 191, 192 (PI. XI), and to the occasional 

 union of this with the radius, figs. 192, 193. However, con- 

 sidering the frequency with which a medial trachea is 



