36 THE MAMMALS, REPTILES, AND FISHES OF ESSEX. 



aquatic species. Its habit of haunting water, whether stag- 

 nant ponds or running streams, flitting with rapid vibrations 

 of the wings a very few inches above the surface, and appar- 

 ently spending most of its time of flight there, makes the 

 description " aquatic " a very exact one. 



Those I have endeavoured to keep appeared delicate, and 

 soon died. Possibly they required aquatic insects, or it 

 may be they could not bear confinement. The members of 

 the entire family appear equally unfitted for close captivity, 

 and I have never succeeded in keeping insectivorous bats 

 alive for any length of time. 



Vespertilio nattereri, KuhL REDDISH-GREY BAT. 



This easily-distinguished bat is reputed to be rare. In 

 the district round Colchester, however, it is one of our com- 

 monest species. It is recorded by Doubleday (Zool., 1843, 

 p. 6) as found at Epping, and Newman also notes (Field, 

 Mar. I4th, 1874, p. 263) that it is not uncommon there. I hear 

 the peculiar squeaking note of this bat during its evening 

 flight more frequently than any other in the streets and gardens 

 of Colchester. 



Houses and buildings are its favourite hiding-places in 

 summer. In winter, cellars, caverns (as those under Colchester 

 Castle), and similar places are generally chosen. Occasion- 

 ally, in the late autumn, bats are brought to me which have 

 been drawn up to the surface in buckets from some of our 

 deepest wells. From my observation that three out of every 

 four are of this .species, I am led to believe that crevices in 

 the brickwork of the wells are chosen by them as hyber- 

 nacula. 



Vespertilio mystacinus, Leisler. WHISKERED BAT. 



The flight of this bat is very similar to that of the Pipistrelle ; 

 and like that animal, it hawks under the shelter of a hedge or 



