Annals of the Transvaal Museum. 
77 
either extremity. Arrangement of the rows of pits on the. ventral surface 
approximately the same as on the dorsal surface ; the remainder of the 
integument formed of zigzag folds passing between and surrounding the 
pits. Stigmatic plates, (II, n) semi-lunate, transverse, opposite Coxae 
IV. Anus a short distance posterior of the level of Coxae IV, 
elliptical, seven hairs on the edge . of each valve. Rostrum (II, l) 
short, set in a pit near anterior end of the body, just anterior of 
first pair of Coxae ; base rectangular, nearty as wide as long ; 
mandibles (II, l, m) with process of inner apophysis tridentate, outer 
apophysis short, with three teeth, the anterior of which is small and sub- 
terminal ; hypostome notched at its extremit}^ in the females (II, Jc), on 
each half, at the tips five to seven small teeth in two trans- 
verse lines, then four strong teeth, disposed two and two, and 
followed by three smaller teeth, below which is a series of teeth becoming 
smaller and smaller and in three, four, and then five longitudinal rows, 
which do not extend to the external border nor further than the middle 
•of the length of the hypostome ; in the male (II, j) eight small teeth at 
the tip, followed by six large teeth in twos, then three small teeth arranged 
irregularty, below which is a series of small blunt teeth as in the female ; 
palpi elongate, the second article perceptibly cylindrical, on their ventral 
side a few small hairs, and on their dorsal side numerous long 
hairs with denticles on the convex edges of the hairs, these hairs a 
little more abundant on the first article than on the second, still less 
numerous on the third and very few on the fourth, the extremity of 
which is truncate and a little concave, and bears twelve to fourteen blunt, 
cylindrical spines ; four long hairs at the base of the rostrum, two of 
which are near the insertion of the palpi. Sexual opening in female, long 
transversely and narrow, situated between Coxae I, in male half as long 
as in female, wider, and situated opposite first inter-coxal space. Legs 
with Coxae slightly striated, those of the first pair a little removed from 
those of the second, second article cylindrical, almost as wide as long ; 
the others a little flat dor soventr ally ; the third and fourth elongate, 
truncate, narrower at the distal extremity, the other two with parallel 
edges, the third longest, the three others of almost the same size ; tarsi 
with the dorsal protuberance usually indicated by a basilar constriction ; 
short hairs on all the articles except the coxae. 
Female up to 10 mm. long by 6 mm. wide ; very flat when young ; of 
.a thickness in the centre almost equal to the half of its width when 
it is engorged. The male may reach 5 mm. long by 3 mm. wide, wi'tli the 
same depressions as the female. 
. Nymph resembles the adult, but without the sexual orifice ; anus wider 
than in larva, five to seven spines on each valve. Mandibles like those of 
adult ; hypostome (II, i) with five to eight small teeth at tip on each half, 
then five large teeth, followed by a series of small blunt teeth, growing 
-smaller posteriorly and in rows of three, then four. 
Larva (I, f) (unengorged), oval in outline, broadly rounded behind and 
more narrowly rounded in front ’ 0.66 to 0.70 mm. long by 0.50 mm. 
wide ; flattened, with marginal and central part of dorsal surface slightly 
raised ; light yellowish or greyish in colour, becoming nearly translucent 
at the margin, from which colourless lines extend toward the centre ; a 
lighter shield-shaped area on the dorsal surface over the rostrum ; surface 
of body with fine parallel transverse and slightly undulating striae ; no 
pits ; edge of body with a marginal row of short folds ; numerous large, 
