0. L. Walton 
large oak and noted how averse is Tabanus to enter the shade; any 
cow venturing forth would be instantly assailed, while those on the 
outskirts would be hurriedly visited and again left. 
VIII. Tabanus cordiger Wiederman. I found this species to be 
fairly abundant at Crosswood in July and early August, 1916. I only 
saw it attack horses, and chiefly the legs and belly. 
The flight is silent, and in habit this species is much slower than 
the others so far mentioned; Verrall (p. 413) records this species from 
Barmouth, on the authority of Col. Yerbury. 
X. C. caecutiens Linn. Although a sharp look out was kept during 
the progress of the Survey, not a single specimen of the genus Chrysops 
was seen until the hot dry weather of July 1916, when a limited number 
of the above two species were obtained. 
Two females of C. quadrata were taken from the head and neck of a 
working horse in a hay-field at Crosswood on July 20th, and similarly 
two of caecutiens on the 28th on a shire mare at Rhos Cellan, near 
Borth. Next day, two females were taken from a shire at Crosswood, 
while one of each species were collected on July 31st. In these cases 
the head and neck were chosen for attack. 
A specimen of Chrysops was noted upon a Kerry sheep on July 30th, 
but not secured. 
Warble Flies ( Hypoderma sps.). 
Whilst visiting the farms of the Survey Area in 1913—14, and again 
in 1914—15, constant attempts were made to obtain information re¬ 
garding these cattle pests. The data gathered, however, did not prove 
to be satisfactory for several reasons, first, the larvae are not obtainable 
throughout the year, and farms visited during some periods naturally 
did not yield results ; again unless the cattle were either in the buildings 
or readily available personal observations were difficult, and the ob¬ 
taining of specimens practically impossible; lastly, the local farmer 
although generally able to say whether his cattle were subject to attack 
or not, could give no help as to which species was present, and not 
infrequently overlooked the pest altogether. 
I therefore decided to make a special series of visits during the 
spring of 1916, to farms throughout the Area at varying altitudes and 
in different situations, in order to gain some definite information on the 
subject. In all twenty-five farms were visited and about 170 cattle 
examined. Samples of larvae were thus obtained from sea level to 
15—2 
