10 
Annals of the Transvaal Museum. 
rump with two deep constrictions ; foot four-jointed, the second segment 
wider than the first, and having a kind of projecting annulus ; spurs 
somewhat long, tapering, without interspace, outcurved ; toes three. 
General Description. — Length, when feeding, about 370//, diameter of 
corona 65^, of neck 40^, of trunk 70//, tip to tip of spurs 25//, length of 
spur 12 to 15^. The discs are large, and the space separating them is 
about equal to half the diameter of a disc. The upper lip is unlobed and 
rounded, but somewhat flattened in the middle. Two lines run from its 
boundary, converging towards the rostrum, enclosing a space shaped like 
the keystone of an arch. There are central setae on the discs. The 
rostrum is broad, with the lamellae apparently separated, and the antenna 
is very short. 
The skinfolds of the trunk are deep, and there are two especially 
pronounced ones running from the central trunk on to the preanal, near 
the median line, a similar pair continuing on to the anal. The anal and 
preanal segments are swollen, and separated by a deep constriction. The 
anal expands at its extreme end into a narrow flange. 
The first segment of the foot is very short. The second is about as 
long as broad, and is broader than the first segment, bearing an annular 
thickening near its anterior edge. The spurs are like those of C. plicata 
Bryce ( 3 ), but they are relatively somewhat shorter. There is nothing 
calling for remark in the internal organization. 
As the name is intended to imply, this species is very closely related 
to C: plicate. It differs in the entire upper lip, the total absence of the 
flanges on the rump, and in the enlarged second foot-segment. The close 
resemblance to C. plicata appears in the keystone form of the central part 
of the upper lip, the folds of the posterior part of the trunk, the deep con- 
strictions bounding the anal and preanal segments, and the form of the 
spurs. Only C. plicata and two related species have those lines on the upper 
lip which give the appearance of a keystone. Some forms of C. plicata 
completely lack the flanges or processes on the rump. The characters 
of lip and foot sufficiently distinguish C. plicatula from such forms of 
C. plicata. 
Like C. plicata it is extremely restless and jerky in its movements, 
and is thus very difficult to observe accurately. 
Habitat — Pretoria, in moss collected by J. Hewitt, April, 1910; 
plentiful. 
Callidina aculeata (Milne) ( 19 ) ; synonym, Macrotrachela aculeata 
Milne (Plate I, figs. 4-6c). ---Three distinct forms were observed. As 
Mr. Milne’s figure is too small to show much detail, and his description is 
somewhat meagre, I will here figure and describe all three as fully as possible. 
First (Fig 5). — Sufficiently near Milne’s type, it has two dorsal 
series of spicules on the anterior trunk, two on the central trunk (one of 
them at the widest part), and three on the ‘ rump ”, The anterior margin 
of the trunk shows two prominences on the dorsal side, and four smaller 
points on the ventral side. The two anterior rows of spicules are continued 
across the ventral side also ; all the other rows are interrupted on the 
ventral side. The ventral surface of the central trunk is transversely 
plicate, and the folds are scalloped. There are some small spicules on 
