SOUTH AFRICAN TKHMITES. 95 



PLATE VII. 



Fig. 78. — Hodotermes viator; wing-sac of nearly mature nymph 

 with the detail of the trachea; ; x., the trachea preceding the c]"oss-rib 

 from post-costa to costa. Post-costal independent. 



Fig. 79. — H. viator; an abnormally reduced inner cubital (Cu.). 



Figs. 80, 81, 82, 83. — H. viator; the cai-dinal trachea and the basal 

 connections of the trachea? of the wing-sac, illustrating abnormal 

 developments. Fig. 80 (? M, in solid black), an extra trachea, probably 

 the medial, originating from the base of (ps.-m.) the outer cubital (or 

 pseudo-medial). Fig. 81, a deeply furcate (or duplicated) post-costal 

 (in solid black). Fig. 82, an extra principal trachea (in solid black) 

 entering the wing-sac and associated with the radial. Fig. 83. the 

 pseudo-medial, cubital, and anal arising almost independently. 



Figs. 84a, b, c, d. — H. viator, normal wings; fig. 84a. fore wing; 

 figs. 84b, c, d, hind wings. 



Figs. 85 and 86. — Calotermes durbanensis; wing-stump and 

 base of lamina ; fig. 85, of fore wing ; fig. 86, of hind wing. 



Fig. 87. — C. durbanensis; part of lamina of hind wing with (in 

 solid black) an independent post-costa. 



Figs. 88-103b represent the development and abnormalities of the 

 tracheae of the wing-sac of 0. durbanensis. Figs. 88-97, 101a and 

 102a are more or less in proportion. 



Pigs. 88-94. — -These illustrate the normal progressive development of 

 the trachea;, commencing from the hinder wing-sac of fig. 88. In 

 fig. 88 the more advanced condition of the tracheae of the meso-thoracic 

 wing-sac (of a moderately young nymph) is well-marked. In fig. 91 the 

 branch to the sub-costal is an unusual feature. In fig. 94 is shown that 

 extension of the principals, and that growth from these of many small 

 trachea?, to be found in the wing-sac of a nymph, in the last stadium, 

 prior to the development of the final wing. 



Fig. 95. — An abnormal medial (in solid black) ; the trachea has two 

 strong outer branches which cross one another and extend to the apex 

 of the sac. 



Fig. 96. — A medial (in solid black) taking an abnormal path in 

 crossing the cubital, and extending to the inner margin of the sac. 



Fig. 97. — An abnormal medial (in solid black) duplicated from the 

 cardinal, the two trachea; crossing. 



Figs. 98a and b.— Illustrating the basal connection of an extra princi- 

 pal trachea with the medial. In fig. 98a the extra trachea is shown in 

 solid black ; in fig. 98b the junction of the two is illustrated. 



