280 CLAUDE FULLER. 



org-aii illustrated by fig. 10, a, represents a development 

 from A (PL XY) to Kb through J. The XVI organ shown in 

 fig. 10, h, is a development from A to GiTb through G, Gil, QJ. 

 The XVI of fig. 10, c, is a development from A to J with a 

 tendency to arrive at Kb. The two XVI-jointed organs [d, e) 

 result from a development through G to G.7. 



The smallest nymphs (second instar) exhibit the XIV 

 expression (stage E), and these progress through G either to 

 H or (jS, so becoming XVI- or XV-jointed. The nymphs of 

 the final instar exhibit antennse articulated like those of the 

 imago. 



Worker. — With both castes the antennae are virtually 

 XV-jointed expressions, such antennse as count XIV being 

 due to the fusing of III, IV of the XV. This in some cases 

 is self-evident, especially in the antennae of the major workers. 

 In others it may not be so clear, and in many minor workers 

 the XIV expression exhibits a simple rather than a compound 

 III. The development of the organ is from stage B (PI. XV) 

 to E and this is the condition after the third ecdysis. In 

 tins stage the flagellum contains 15 elements, as in the third 

 instar (fig. 10,/), four of which are compressed more or less 

 into III. Of these the more distal, the element of (12) is 

 the most developed, and it depends upon the extent of its 

 development whether the organ remains XIV- or becomes 

 pseudo- or actually XV-jointed. The variable length of III 

 which obtains with different species or wdth the same species, 

 especially with the incipient and juvenile forms, depends 

 upon the development of the elemental region of such an 

 organ as that represented by fig. 10,/. 



Nasuti. — In his synopsis of the sub-genus Trinervi- 

 termes Holmgren gives the number of joints for nasuti 

 antennae as XII, XIII and XIV. As I have obtained 

 ordinary and pteroergate nasuti of T. trinervif ormis with 

 XV-jointed antennas, the synopsis needs to be extended to 

 include these forms. 



Some authors give the joints as XII or XIII and as XIII or 

 XIV, and occasionally it may be gathered from the description 



