Annals of the Transvaal Museum 
47 
1 6. Shaft of flagellum extending backwards about as far as the basal 
enlargement: at the anterior bend it presents the appearance o.f a broad stiff 
membrane: this quickly becomes much broader, but at the same time is 
strongly folded longitudinally along the middle, so that a transverse section 
of the flagellum at about the middle point of its length would be V-shaped, 
the angle being directed upwards and forming the upper margin of the flagellum 
in side view. In the apical third, the membrane tapers gradually, the apex 
being not very sharp, and at a short distance therefrom on the inner side is a 
strong accessory tooth. The single dorsal tooth on the inner side of the fang 
projects forwards and is long and strong. 5 . ferox Pocock. 
17. Shaft of flagellum reaching back to a point which is a little further 
from the hind margin of the basal enlargement than this from the anterior 
bend. Tip of flagellum pointed and barbed somewhat like an arrowhead: the 
terminal portion is also armed at the base with two strong serrate teeth, one 
external and the other inferior. 5 . sagittavia Pocock. 
18. Tip of flagellum nearer to the posterior margin of the basal enlarge- 
ment than is that margin to the anterior bend. Apex blunt. At the anterior 
bend, the shaft is very broad, becoming strongly twisted as it passes backwards : 
not far from the apex, its upper edge presents a small sharp tooth. On the 
inner dorsal edge of the fang of the upper jaw, there are two small tubercles 
near to the anterior bend of the flagellum. 5 . suffusca Hewitt. 
F. Like D, but flagellum a little longer and the anterior bend 
situated further back over the intermediate small teeth. 
19. Recurrent portion of flagellum reaching back a little beyond the 
posterior border of the basal enlargement, and becoming gradually attenuated 
at the tip : basal enlargement with a high crest and upright posterior border. 
5 . darlingi Poc. 
20. Recurrent portion a little longer than in darlingi, running backwards 
and upwards at an angle of 45 0 , straight throughout the greater portion of its 
length but distinctly sinuate in the distal fourth, the apex being directed 
upwards : basal lamina not so elevated, its outline about semicircular. Head- 
plate, mandibles and abdomen with black stripes. S. sericea Poc. 
21. Flagellum still longer, gradually tapering to a slender apex, which is 
situated about midway between the anterior bend and the ocular tubercle; 
shaft doubly sinuate from side to side and strongly curved in a vertical plane 
in its distal half, the apex being directed downwards. Basal enlargement high 
and almost circular in outline. 5 . alstoni Purcell. 
22. Shaft of flagellum strongly flattened over the first portion of its length, 
then becoming abruptly narrowed distally so that the apical third or fourth 
is setiform : total length of recurrent portion equal to about twice the distance 
between the anterior bend and the hind margin of the basal enlargement, which 
is rounded in outline. First tooth of lower jaw situated midway between the 
second tooth and the tip of the fang: lower jaw with feathered bristles on its 
inner surface. Upper jaw with no distinct tooth on the superior inner margin 
near the base of the fang. Dorsal surfaces with blackish stripes. 
5 . celeripes Hirst. 
G. Shaft of flagellum short, directed forwards and extending 
about as far as the tip of the fang or even a little anterior thereto, 
