CAIRO 
431 
Klug, was to be seen running at a moderate pace in all directions; 
Tentyria glabra, on the other hand, is a comparatively sluggish insect 
found under stones. The little Zophosis complanata , Sol., is ex¬ 
ceptionally swift in its movements, curvetting about so as to give 
much trouble to its would-be captor. It frequented desert plants, 
from which, when disturbed, it would make short excursions on to the 
open sand, returning again to its shelter. The integuments of this 
beetle are hard and brittle ; in the cabinet it appears as a uniformly 
black insect, but on the desert closely approximates in colour to the 
sand, being dust-coloured, with a tendency to red, but sometimes 
appearing almost white in the bright sunlight. This colour is due to 
a coating easily rubbed off by the fingers, disappearing entirely in the 
cyanide-bottle; it seems to consist of an excretion, perhaps waxy in 
its nature, to which probably the finer dust of the desert adheres and 
gives the last touch to its cryptic colouring. 1 Under stones an Ocnera 
hispida turned up, as well as another species of the same genus. 
The Ant of the place was an Aphaenog aster, which Mr. Morice thinks 
may be a race of barbara. 
On the Mukattam Hills, above the Citadel, hills of white lime¬ 
stone built up mainly of Nummulites and other fossils, I found under 
stones the common Ocnera hispida, Micipsa grandis, Kraatz, and 
three specimens of a species of Adesmia. Inside the Citadel itself I 
found a worker Myrmecocystus viaticus carrying a brother in his 
mandibles. 
The most promising locality that I visited was the Wadi Hof, a 
few miles to the East of Helwan. This is a winding gorge cutting 
through the limestone hills, bounded on either side by steep cliffs, 
but without any stream at the bottom. These gorges are one of the 
puzzles of Egypt, and seem to point to a time when rain was much 
more abundant than now, for it seems very difficult to suppose that 
such rain-storms as undoubtedly occur from time to time can have 
performed such extensive works of excavation. At the bottom of the 
Wadi there is little sand, but many stones. Small slender Lizards, 
exactly the colour of the ground, were to be seen in abundance running 
swiftly along with their heads held high. Vegetation was more 
varied and more abundant than one at first imagined; it would have 
been delightful to have had more time there, and especially to have 
visited it later in the year or in a less dry spring. However, I 
succeeded in netting that regular desert insect, Melitaea didyma, Esp., 
f. deserticola , Oberth., which I had previously taken in a somewhat 
similar locality near Biskra. Another specimen was unfortunately 
1 See above, p. 163. 
