C. L. Walton 
ten days later a number were taken sucking blood from the belly of a 
working horse, in the same locality. Some of the flies were engorged 
with blood. 
III. S. ornatum Meigen. One specimen. Crosswood, early August, 
from the belly of a working mare. 
I am indebted to Mr F. W. Edwards 1 for this identification and also 
for verifying that of S. variegatum. Both species were taken in the 
evening and none were observed during the heat of the day although 
searched for. 
IV. Haematopotd pluvialis Linn. This is an exceedingly abundant 
form after mid-June, and in the lowland country is a great pest to 
working horses. On June 28th, 1914, on the wooded bank of the 
Ystwyth I counted between thirty and forty upon the back of a man 
wearing a dark coat, and at Crosswood on June 21st, 1915, I killed 
200 upon four working horses in a few minutes. 
In 1916 they were present in great numbers, especially during the 
hot dry weather of July and early August. Rain and cool winds at 
once mitigate this pest. Many were examined but none of the other 
species of the genus were detected. The earhest date for the species 
in my notes is June 8th, 1915, near Talybont, one specimen in the 
grip of an Asilid fly; I was bitten at Crosswood on the 10th, and saw 
the fly in abundance at Llanfarian, near Aberystwyth on the 12th. 
V. Therioplectes distinguendus Verrall. This beautiful species was 
common at Crosswood and also near Aberystwyth, attacking horses 
during July and early August 1916. At first I took it to be T. solititialis, 
but the characters agree with Verrall’s distinguendus. 
In every case the abdomen was “very extensively bright brownish 
orange, even to the fourth segment 2 ,” though there is a considerable 
amount of variation in the black dorsal central line. The belly and 
legs of the horses were invariably the parts attacked. The flight is 
silent, and the $ is easy to capture once she has settled. Cattle are 
also attacked. 
VI. Atylotusfulvus Meigen. I obtained two females while they were 
sucking blood from horses at Crosswood during July 1916, and one 
similarly on August 1st. I also observed but failed to capture three 
others. This handsome fly possesses a rapid and silent flight, and is 
by no means easy to obtain being very readily alarmed. 
1 Edwards, F. W. “British Species of Simulium,” Bull. Ent. Research, Vol. vr. June 
1915: 
2 British Flies, Vol. v, p. 371 et seep 
Parasitology x 
15 
