A Monograph of the Formicidae of South Africa. 673 



at an angle, (this is easily seen when the head is looked at from 

 the side). The front edge of the shelf is fringed with a row of 

 long bristles or ammochaetae, curving downwards and forming a sort 

 of moustache. A similar row of bristles, curving forwards and up- 

 wards is placed behind the mouth on the ventral surface of the 

 head. In a groove on the basal margin of the mandibles there is 

 another fringe of such bristles, but less coarse than those on the 

 clypeus, and the lower surface of the mandibles is also furnished 

 with one or two rows of long and thin hairs, directed inwards. 

 The thorax is not unlike that of the Myrmoturba group, but is more 

 robust, and the epinotum is less compressed, its dorsum less cristate. 

 Scale of petiole thick below, acuminate and trenchant above ; the 

 anterior face has its basal half vertical and the upper half oblique, 

 so that a rounded, ill-defined angle is seen when the scale is 

 looked at from the side. 



f 

 $ media and minor. Head longer than in the %, but not much 

 longer than wide, usually a little wider in front than behind. The 

 clypeus, ammochaetae etc. as in the %. Scale of petiole thicker. 



9- Head like that of the § media, but equilateral. 



(?. Clypeus with ammochaetae as in the 9 an d & Mandibles 

 long and narrow. 



The members of this subgenus, which is confined to the S. Afri- 

 can Region, are adapted for living in sandy localities, like the 

 Ocymyrmicini which are also provided with ammochaetae. 



Key to the species of the sub-genus Myrmopsamma. 



(2) 1. Scapes with an angular dilatation or lobe near the base in front; clypeus 



without a moustache ..... cuneiscapus, Forel. 

 (1) 2. Scapes simple; clypeus with a moustache. 

 (6) 3. Head of the 2J_ not very deeply emarginate behind, the depth of the 



emargination less than half the length of the eye. Colour of head and 



thorax not dark brownish red, abdomen not black. 

 (5) 4. Head moderately emarginate behind ; colour of head and thorax more or 



less yellowish red or red .... mystactus, Emery. 

 (4) 5. Head barely emarginate behind ; colour pale ochreous 



mystaceus, var. exsanguis, Forel. 



(3) 6. Head and thorax very dark brownish red ; posterior emargination of the 



head in the 2J. as deep as the eye is long, mystaceus, var. kamae, Forel. 



