100 CLAUDK FULLER. 



Fig. 166. — R. putorius; the cardinal and bases of the tracheae 

 illustrated in fig. 165. 



Psammotermes allocerus. 

 Fig. 167. — Fore wing with a well-developed media. 

 Fig. 168. — Hind wing with a well-developed media. 

 Figs. 169 to 173. — A series of wings in which the media is absent and 

 the cubitus variously developed. 



PLATE XI. 

 Termes natalensis. 



Fig. 174 — Normal wing; E. with one sector. 



Fig. 175. — Normal wing ; B. with three sectors. 



Fig. 176.^ — Wing-sac showing tracheation displayed prior to final 

 ecdysis. 



Fig. 177. — A part of fig. 176 ; more enlarged, illustrating the marginal 

 thickening. 



Fig. 178. — A part of fig. 1 76 ; gi-eatly enlarged, illustrating the sub- 

 division and spreading of the cubital offsets on approaching the marginal 

 thickening. 



Fig. 179. — Cardinal ti-achea of mesothorax, showing the genesis of 

 the trachea of the wing-sac. 



Fig. 180.— Cardinal trachea of metathorax, showing a more advanced 

 condition than that of the mesothorax (fig. 179). 



Fig. 181. — Wing-sacs of very young nymph, illustrating early form 

 of principals ; a post -costal is present in the anterior organ only. 



Figs. 182 to 187. — The cardinal trachea and the basal attachments of 

 the principal tracheae of the wing-sac as seen in fairly mature nymphs. 



Fig. 182. — The post-costal has an independent base between that of 

 the radial and the leg trachea ; the anal is well-developed and directed 

 into the thoracic cavity. 



Fig. 183. — The post-costal emerges from the base of a bunch of 

 tracheas which lies well in front of the leg trachea ; the base of the 

 radial is fused with that of the cubital; the anal is missing. 



Fig. 184. — The post-costal arises from the stock of the radial (as in 

 Hodo-, Calo-. and Cryptotermes) ; the anal is atrophied. 



Fig. 185. — The post-costal is attached similarly to the case illustrated 

 by fig. 184, but is subdivided ; the base of the radial is more or less as 

 in the case illustrated l:)y fig. 183 ; here also the anal is missing. 



