36i 

 YORKSHIRE BATS. 



H. B. BOOTH, F.Z.S., M.B.O.U. 



The Barbastelle Bat at Helmsley. — As this species 

 was only added to the county list last year [The Naturalist, 

 1920 pp. 379-80), Mr. F. H. Edmondson and I spent the 

 hrst week-end in June at Helmsley with Mr. A. Gordon, in 

 order to make further investigations. Our efforts were 

 successful, and I am glad to say that the Barbastelle appears 



Immature male Barbastelle (about 6 weeks old), and adult male Barbastelle. 



About fths natural size. 



to be well established, and in some numbers there. On the 

 evening of June 4th, in the basement of an old ruin in Dun- 

 combe Park, we found two adjacent colonies, which we es- 

 timated contained about forty bats each. In both colonies 

 they all came out almost together, like a shower. We man- 

 aged, however, to secure four, all pregnant females. I 

 dissected one, and as the embryo measured seven-twelfths of 

 an inch as it was released from the uterus — and in a semi- 

 circular position — it was very evident that birth would have 

 taken place within two or three weeks 'at the latest. 



As so little appears to be known of the breeding of the 

 Barbastelle, we returned to the ruin on the following evening 

 with some borrowed angler's landing-nets to try to get some 

 undamaged females. The bats had evidently changed their 

 quarters, but as on the evening before several kept returning 

 to the building, with difficulty we managed to net one — another 

 pregnant female. This we left the next morning, on our way 

 home, to the care of Mr. Riley Fortune, so that he might 



1921 Nov. 1 



