SOUTH AFRICAN TERMITES. 75 



principal ribs are similar to those of Caloteriues. That the 

 generic character is not constant may be gathered from figs. 

 148 and 150 (PL X) ; it is true both the wings illustrated have 

 an extra principal rib, but a normal wing has been found in 

 which the media extended to the apex. Many wings are to 

 be found in which the media possesses a strong branch or 

 sector to the apex, such as those illustrated by figs. 143, 146 

 (PI. X). This is seemingly the case in fig. 149, but here the 

 condition appears due to the intrusion of an extra principal 

 trachea into the wing-sac. 



Cryptotermes wings differ strikingly from those of 

 Hodotermes and Calotermes in the complete absence of 

 reticulation. In many wings there are no ridges w^iatever ; 

 in others, again, there are curiously curved and erratically 

 arranged ribs or ci'oss-ribs exterior to the cubitus in the apical 

 quarter, and these sometimes occur between the media and 

 radius as in fig. 143. Where the media has no branch, the 

 cubitus tends to invade its field, figs. 144, 147. " Indepen- 

 dent " ribs are not uncommon ; and they may appear actually 

 independent as in fig. 152 or can be seen to be incurvings of 

 the ciibitus offsets as in figs. 146, 149. 



Abnormalities due to the presence of extra principal 

 tracheas in the wing-sacs are to be met wnth, but not so 

 frequently as in Calotermes. Such as have been found ai'e 

 traceable to a duplication of either the medial or the cubital 

 ti'achea. Figs. 148, 149, 151 illustrate wings which seem to 

 owe the unusual arrangement of the ribs to a duplicated 

 cubital, whereas fig. 150 represents a duplication of the 

 medial. In neither Hodotermes nor Calotermes was a 

 hind wing found in which the pseudo-media or media did not 

 attach itself more or less conspicuously to the radius ; but one 

 hind wing of Cryptotermes, fig. 152, shows the media 

 attached to the cubitus. 



The development of the trachea? of the wing-sac has been 

 dealt with elsewhere, and is similar to that of Calotermes, 

 except there is no secondary development of many fibril- 

 like tracheae. A few do develop and are the predecessors of 



