322 DR. A. E. SHIPLEY ON [ Mar. 16, 
Fig. 24 shows the inner surface of the same, and on Pl. XLIII. 
will be found a coloured sketch of a foot seen obliquely. From 
these drawings, which have been prepared for me by Mr. Edwin 
Wilson of Cambridge, it will be seen that the large paired 
claws are double, and that whereas the distal limb of each claw 
is slender and very sharply pointed, the proximal limb is much 
stouter and ends bluntly. Between the claws is a median, 
feathered, process with hairs or bristles, and at the base of each 
double claw is a pulvillus covered with minute hairs. As fig. 24 
shows, there are other processes for which I have no name. 
The arrangement of the hairs is faithfully given in the drawings. 
We do not know the exact relations of the grouse-fly to the 
grouse. It is believed to suck its blood, and it will certainly bite 
human beings. For a time it seems to burrow amongst the 
feathers of the bird, and anyone handling grouse during the 
summer is likely to disturb a fly or two. They come buzzing out 
and are apt to crawl up one’s sleeve by aid of the pair of great 
hooked claws on their feet. Altogether they have a sinister 
aspect, and to people who do not like flies they are very repellent. 
They occur freely in larders where freshly-killed grouse have 
been placed, and after a short time they leave their dead host and 
accumulate upon the windows. 
The earliest month we have found the grouse-fly is in June, 
towards the end. The latest we have found up till the present 
time is September. Mrs. Duff Dunbar has taken them as late as 
October. Perhaps they are most plentiful in August. 
The females seem to be commoner than the males, or, it may 
be, in August are more readily taken. Like other members of 
the Hippoboscidee, which includes the horse-fly, forest-fly, and 
sheep-tick, the grouse-fly does not lay eggs, but the ovaries pro- 
duce one large ovum at a time, and this passes into a dilated 
oviduct which acts as a uterus, and here the egg develops. After 
attaining a certain stage of development, the larva surrounds 
itself with a pupa-skin and is extruded. The chitin covering the 
larva hardens and blackens with exposure to the air, and forms 
the so-called pupa-case ; in fact, one may almost say the young 
are hatched as pup. At no time is the larva exposed, though 
there is a larval stage free in the uterus wrapped first in the 
egg-sheil and then in the pupa-case. 
When first deposited the pupz are light in colour and the case 
has not hardened. Those dissected out from a fly are shorter 
and more squat than the mature pupe found on the ground 
(compare a and 6 in fig. 25, Pl. XLIV.), and the symmetrical 
ridges and elevations are much less well marked (Pl. XLIYV. 
fig. 25,d &c). The mature pupe are shown from above, from the 
side, and from the micropylar end in Pl. XLIV. fig. 25, ¢, e, & f, 
highly magnified. Between them they show well the six elevated 
and cross-barred ridges which radiate from the micropyle to the 
angles of the hexagonal micropylar area. 
The pupz were found during August and September. They 
