THE SEROTINE 135 



of lower leg ; fifth metacarpal, about -93 of third ; lower leg, about 

 • 39 of forearm and about -28 of head and body. 



Skull: — Greatest length, 21; basal length in middle line, 16; 

 palatal length in middle line, 8-5 ; from posterior border of third upper 

 molar to anterior border of canine, 7 ; same in lower jaw, 8-5 ; greatest 

 breadth at zygoma, 14 ; posterior breadth, 9 ; breadth between orbits, 7 ; 

 breadth at constriction, 4-5. 



Weight of a male from Essex, f oz.= 113 grammes (Miller Christy, 

 Zoologist, 1894, 424). 



Distinguishing characters : — As compared with the Noctule, which 

 alone of preceding species is of similar size, this bat is deep brown, 

 with lighter under side, instead of wholly coloured reddish brown ; 

 the colour is alone distinctive, but the cumulative evidence of broader 

 wing, longer ear and tragus, slight post-calcarial lobe, and greater 

 length of tail outside the interfemoral membrane, make error in identifi- 

 cation impossible. 



The Serotine, notwithstanding the clear and intelligible 

 description of its discoverer Daubenton, was mistaken for 

 the Noctule by Isidore Geoffroy, but was well figured in the 

 eighth volume of Buffon's great work. It is in the British 

 Islands only known from the south, and particularly the south- 

 east of England, where it is abundant, and perhaps the com- 

 monest bat, a very remarkable fact when it is remembered that 

 outside of Britain probably no bat has a wider distribution. 



This fine bat has orained its name from the late hour at 

 which it is supposed to commence its evening flights. But 

 in this respect, and in other aspects of its natural history, 

 it has been frequently confused with the Noctule, and there 

 is no doubt that much that has been written of it is 

 incorrect. Thus, nearly every account of it — and the most 

 original are those of William Borrer,^ G. B. Buckton,^ Frederick 

 Bond,^ and George Dowker*— mentions two quite distinct forms 

 of flight, difficult to reconcile as appertaining to the same 

 creature, and inconsistent with the descriptions of the best 

 foreign naturalists. In the first the bat is shown flying 

 with great strength at a high elevation in manner strongly 

 suggestive of the Noctule. In the second it appears as a 



' Zoologist^ 1874, 4126. 2 Proc. Linn. Soc. (London), 6th Dec. 1853, 260 (1855). 

 ^ Field., 14th March 1874, 263 (quoted by Edward Newman). 

 * Zoologist., 1 891, 305-306 and 425. 



