On a new genus of Ixodoidea. 
401 
a strong retrograde ventral tooth, and an inwardly-directed flange- 
like process difficult to see in situ and bearing hairs on its margin 
(see Fig. 14); a slight ventral retrograde process on article 3; 
hypostome 3|3, rather spatulate. Legs strong; coxa I with two 
strong spurs, near together, projecting well over coxa II, also a 
third anterior spur directed over the trochanter ; coxae II and III 
with a conical outer spur and a blade-like inner spur ; coxa IV, 
which is much the largest, with two strong spurs rather near 
together and somewhat diverging, the inner reaching to the 
anus, the outer about half as long (Fig. 12); a dorsal spur on 
trochanter I. Other articles as in Dermacentor. Numerous 
strong short spines on all the articles. 
Female (unfed), L. 4‘2, W. 2'6 mm. (Fig. 13 B). Scutum 
about as long as broad (2‘1 x 23 mm.), with few punctations as 
in </ ; posterior border sinuous ; eyes obscure, slightly anterior to 
the lateral angles ; cervical grooves of moderate length ; lateral 
grooves parallel, the sides of the scutum being very prominent 
and darker in colour; marginal grooves extending backward to 
include the two extreme festoons. Venter : spiracles short comma- 
shaped (as in A. versicolor, Fig. 29 $). Capitulum (11 mm, l .) 
base less protuberant laterally than in f and with only slight 
cornua ; palps much longer than in f and with rounded lateral 
contour. Legs (Fig. 13 G) long and strong; the coxae do not differ 
greatly in size and they are spurred as in f except that the spurs 
on coxae II— III are longer while the spurs on coxa IV are sub- 
equal and short. 
Origin. Description based on 3 f and 1 $ collected by 
Dr Old in North Nyassa, British Central Africa. Host not stated 
(preserved in 5 °/ 0 formalin, then in spirit). We have also received 
a fully gorged $ collected by Dr A. Yale Massey at Kansanshi, 
N.W. Rhodesia, which was found in a dwelling. It agrees almost 
precisely with our $ , its scutum measures 2*3 x 2'6 mm., but the 
legs are much stouter. It is a large specimen : L. 16*9, W. 14 mm. 
Notwithstanding its gorged condition the festoons are still well- 
marked. 
Note. — The Digit (Fig. 15) of $ 165 g long, short and thick with dorsal 
process very stout, transverse, bidentate externally ; external article with 
small distal tooth followed by a large tooth. The foveolae of £ small, 80 g 
across, round, the interval between them 170 g (see Fig. 13 A where they 
lie posterior to a central group of punctations of about the same size). 
