THE PARTI-COLOURED BAT 139 



diagnostic. Both species have a band of hair on the arm, so 

 that this point is of no value for purposes of determination. 



On the wing, the Serotine can only be confused with two 

 other British bats, the Noctule and the Greater Horseshoe. 

 Its flight has already been compared with that of the former, 

 which rarely descends to hunt insects around the lower branches 

 of trees, and both are conspicuous enough to exhibit the 

 different proportions of their wings in flight. 



[THE PARTI-COLOURED BAT. 

 VESPERTILIO MURINUS, Linnseus.i 



The Parti-coloured Bat was included in the British list 

 by Bell, on the strength of a single specimen taken by 

 W. E. Leach at Plymouth, probably in the early thirties, 

 and now in the British Museum.^ A second example came 

 into the hands of John Hancock when "either alive or just 

 dead." It was taken (as he wrote to Mr Thomas Southwell), 

 " I am almost sure, on board ship, undoubtedly off Yarmouth 

 Roads, in the year 1834."^ 



The coloration of this species is so remarkable that, were 

 it a true native of Britain, it could not for so long have escaped 

 the attention of zoologists. We may, therefore, conclude 

 that its visits to this country have been entirely accidental. 

 Possibly they may have been effected by the assistance of 

 shipping, or it may be that the individuals which have reached 

 our shores have been blown across the Channel while engaged 

 in the migratory movements which both the Parti-coloured 

 and its ally, Nilsson's Arctic Bat,* are believed to perform 

 annually. With the prevailing winds blowing from and not 

 to the British Isles, however, its frequent occurrence within our 

 boundaries would seem to be improbable. 



1 Systema Naturae, x., 32 (7), 1758 : until recently cited as Vespertilio discolor of 

 Natterer. 



^ No. 37a. 



' Southwell, Trans. Norfolk and Norwich Nat. Soc, 1873-74, 80 ; (I am indebted 

 to Southwell for further particulars by letter) ; E. Newman, Field, 7th March 1874, 

 218, and Field, 5th Sept. 1874, 246. 



'' V. nilssoni. 



