OUSERVATIOXS OX SOME SOUTH AFEICAN TERMITES. 415 



and the apical joint. However, it is a far more satisfactory 

 method than endeavouring to trace elusive apical margins. 



Terms. — VV^ith regard to the descriptive terms these will 

 be found to follow very closely those of Comstock and Kellog 

 (5). The general terminology also follows these authors, 

 Comstock and Chujiro Kochi (6) and J. B. Smith's ' Glossary 

 of Entomology ' (7). Perhaps the only term used at variance 

 with these authorities is " f rons/' which is given preference 

 to " front.'' Not unnaturally some descriptive terms have 

 been used in a restricted sense, a few terms have been 

 borrowed from allied natural sciences, and some at least have 

 been invented. To avoid any confusion a short glossary is 

 given (see Appendix) so that it will be only necessary to 

 indicate here the application of the terms '' frontal area," 

 " frontal folds" and " ventral genee." 



" Frontal area" is an inclusive term embracing the areas of 

 the frons and the clypeus in those cases where the Y-shaped 

 suture of the epicranium and the clypeo-frontal suture are 

 both obsolete. Thus "frons" is only used when the area is 

 demarcated by a decided Y-suture or by some iutra-chiti- 

 nous trace of it. 



The suture (clypeo-frontal) dividing the frons from the 

 clypeus is present in workers, other than those of H o do- 

 te rmes, and in all imagos ; but in all the soldiers it is to be 

 regarded as obsolete, except in the case of Rlii note rmes 

 putorius, where it is fully expressed. Its probable position 

 is indicated to one degree or another in all soldiers by the 

 features to which I have applied the term " frontal folds." 

 These folds arise at the point of articulation of the mandible 

 and usually extend obliquely backwards more or less into the 

 median region of the frontal area. They are striking features 

 in the soldiers and workers of Hodotermes, and in all cases 

 it appears as if the lateral portions of the original suture were 

 overgrown by a fold of the frons. The folds are actually the 

 points of attachment of the props of the tentorium, and they 

 are heavily marked owing to the thickness of the chitin, and 

 a greater depth of colour occurs in the form of paired oblique 



