o 



02 An7ials Entomological Society of America [Vol. XII, 



Isoptera. 



Two species of this order were examined, Termopsis angusti- 

 collis Hagen and Leucotermes flavipes Kollar. The former is 

 less degenerate in the structure of the genitalia and is therefore 

 more favorable for comparison with other groups, besides being 

 a much larger insect ; so that the following remarks, unless other- 

 wise stated, refer to this species. 



The abdomen (Figs. 60, 61), is tolerably broad and flattened, 

 not unlike that of a cockroach in appearance, though the tergites 

 are more uniform in size, the eighth, ninth and tenth being 

 much abbreviated only towards the lateral margins. As in 

 the Mantids and Blattids, the tenth tergite is prolonged over 

 the supra-anal plate, which is obsolete in the adult; the 

 paraprocts are broad, subtriangular and more distinctly, 

 though not heavily, chitinized, and the short cylindrical 

 cerci are composed of five segments, of which the apical 

 one is much the longest and is probably compound. Termopsis 

 also agrees with these two families in the concealment of the 

 genitalia and sternal regions of segments eight and nine in a 

 "genital cavity," under cover of the backward prolongation of 

 the seventh sternum or "subgenital plate." As mentioned 

 under the account of the Blattoidea, this plate is regarded by 

 Crampton as the eighth sternum, but this is certainly erroneous.- 

 If the seventh sternum is cut away, a small chitinized flap is 

 found, overlapping the genital orifice and also covering the bases 

 of a pair of flattened lobes. This flap represents the free edge 

 of the eighth sternum and the two lobes are the ventral valves. 

 On each side of the lobes is a pair of plates, corresponding in 

 position to the valvifers of the cockroach and, like the latter, 

 thickened along the front margin. These plates are evidently 

 the valvifers, the thickening representing the usual apodeme 

 which occurs on the margin. It is not, however, continued 

 laterad of the valviferj there being nothing here to mark the 

 line of junction of the eighth and ninth sterna. 



Behind the overlapping by the ventral valves is a slender 

 V-shaped sclerite. This appears to represent the vestiges of 

 the two slender bars which meet in a similar position in Par- 

 coblatta and were interpreted as the inferior apophyses of the 

 dorsal valvulse, meeting in the inferior intervalvula. They at 

 least represent some part of the bases of the dorsal valvulae 



