414 CLAUDE FULLER. 



important as those that are moi-e in evidence. The various 

 antenna3 of the different adult castes have much specific vahie 

 provided the limitations of the caste variation and their mode 

 of growth are known. The colour effect of the chitin as 

 overlying muscular tissue is given without attempting 

 diffei'entiation j this seems to be the usual practice. Unless 

 otherwise stated, they are taken from material pi'eserved 

 in 75 per cent, alcohol. In certain species the colour tones 

 and the colour patterns of the head are fairly constant, in other 

 species they are not. Wliilst of assistance in diagnosis neither 

 should be regarded as of great specific value. In general 

 the length of the head with the mandibles and its greatest 

 breadth are secondary aids to diagnosis, Avhilst the total length 

 of the insect is a very deceptive measurement, as illustrated 

 in the subsequent discussion of Term es natalensis. Here 

 it may be mentioned that the various measurements given in 

 the description are only to be regarded as approximate, 

 whether given in mm. or ju. They have one value insomuch 

 as all have been taken by the same means. Total length, 

 head with mandibles and head-width have been determined 

 by placing insects which have died in a more or less extended 

 position npon a plane surface cross-ruled to half a millimetre 

 and then reading off the length with a magnif3dng glass of 

 low power. This method permits the taking of long series of 

 approximate measurements rapidly ; by various checks I 

 have found the results quite as reliable as measurements taken 

 by more laborious and elaborate methods. Whilst the lengths 

 of the soldiers are for fully extended insects, or those in which 

 the long axis of the head is continuous with that of the body, 

 the lengths of the workers are for insects with the head in 

 the natural position at right angles to the long axis of the 

 body. 



The lengths for the antennal segments are approximately 

 the length of the chitinised*portion of the joint and are taken 

 along the middle line of the joint. This omits the conjunctiva, 

 and it does not give the full length of such joints as have a 

 soft telescopic apex — all but two or three of the basal joints 



