612 Annals of the South African Museum. 



The genus has recently been divided by Dr. Forel * into 25 sub- 

 genera, of which 13 are represented in our region. These subgenera 

 are characterised by Dr. Forel as follows : 



1. Sub-genus CAMPONOTUS, Mayr, s. str. 



Type G. herculeanus L. Mandibles with 4 or 5 teeth, rarely 6. 

 Clypeus neither carinate nor lobed. Head not truncate. Dorsum of 

 thorax convex, neither excised nor marginate, widened in front, 

 narrowed behind. Species usually large, robust and usually lignico- 

 lous, excavating galleries in wood. With transitions towards Myrmo- 

 turba. In all countries excepting Australia. 



2. Sub-genus MYRMOTURBA, Forel. 



Type C. maculatus F. Mandibles with 7 or 8 teeth, rarely 6. 

 Clypeus lobed and carinate. Dorsum of thorax convex, neither excised 

 nor marginate, widened in front, narrowed behind. Head of § minor 

 nearly always with a distinct hind margin. Living in the ground or 

 under stones. 



3. Sub-genus MYRMOPHYMA, Forel. 



Type C. quadrisectus Smith. Vertex of head more or less strongly 

 swollen. Otherwise in shape and stature similar to Mymiolurba. The 

 clypeus, however, is more often without a carina and has a lobe 

 which is narrowed and often dentate or emarginate in front. Man- 

 dibles usually with 6 teeth. Australian, Malayan and African. With 

 transitions towards Myrmoturba. 



4 Sub-genus MYRMOPSAMMA, Forel. 



Type C. mystaceus Emery. Mandibles 5-dentate. Clypeus not 

 carinate. Anterior margin of the head, above and below, and often 

 the upper third of the clypeus furnished with transverse rows of long 

 psammophore bristles or ammochaetae. Form of the body similar to 

 that of Myrmoturba. African species of arenicolous habits. The scape 

 sometimes has a dentiform process at the base. 



5. Sub-genus DINOMYRMEX, Ashmead. 



Type C. gigas Latr. . Very large or long species. Head of the 

 § minor narrowed behind into a neck, or at least with the posterior 

 margin reduced to the limits of the articular border, i. e. obsolete. 

 Otherwise like Myrmoturba. 



* See Mem. Soc. Ent. Belg. Vol. 20, pp. 87 et seq. 1912 and Rev. Suisse 

 Zool. Vol. 22, pp. 257—275, 1914. 



