Whitaker : The Hairy-Armed Bat. 385 
It was satisfactory to know that the species occurred in the 
district, but a serious obstacle to learning much of its habits 
lay in its very close resemblance to the Noctule. 
In August, 1906, Mr. Sykes, of Old Mill, near Barnsley, 
mentioned to me that he had frequently observed a number of 
large bats flying about the vicinity of his house at dusk, and, 
at his suggestion, Mr. Wakefield and I met him there on the 
evening of August 18th. 
We walked along a pasture which skirts the upper side of a 
long, narrow plantation covering a steep bank lying between this 
field and the river Dearne. The plantation is composed almost 
entirely of oak trees of fair growth; these we examined care- 
fully, and I climbed up to several likely holes without finding 
anything. 
By this time it was getting dusk, and several fairly large 
bats made their appearance and commenced to hawk up and 
down the top edge of the plantation, at about the elevation of 
the tree tops. They resembled the Noctule in flight so closely, 
that at the time I had no idea but that they were bats of this 
species. 
We failed to see any of them leave their den, and, as it 
quickly grew darker, we began to dispair of being able to 
locate their retreat that night. Just as we were about to leave, 
however, Mr. Wakefield noticed one of them disappear some- 
where in the dead top of one of the oak trees. Upon ascending 
the tree I soon found their hiding-place, which was at a greater 
elevation than any Noctules’ den | have yet examined. The 
top portion of the tree was dead and without twigs, but a few 
of the larger branches remained, and it was through a hole in 
a short stump of one of these, which projected at about right 
angles from the trunk, that the bats found an entrance to a 
hollow in the trunk itself. 
The height from the ground to the hole was about forty 
feet. JI could hear the bats squeaking and shuffling about 
inside, but the. opening was only about two inches diameter, 
and the surrounding wood otherwise comparatively sound, so 
that it was impossible for me to get my hand in or break into 
the den without tools. Moreover, it would have been foolish to 
have made any attempt to examine the colony at the time, as 
some of the bats were still out feeding in the vicinity, and it 
was also getting quite dark. So we left them undisturbed for 
the time being. 
On the 22nd of August I revisited the tree, in company 
1907 November 1. 
