1915.] §7 



row of lateral ones, of which the last, which is placed at the apical 

 margin, is also broad, apex with small pointed hook. Upper bristle 

 of clasper slisfhtly longer and proximally thicker than lower one. 

 Posterior margin of finger very strongly convex beyond the centre, 

 where the ringer is broadest. Finger much wider than in octactenus. 



9 . No differences from ? octactenvs have as yet been discovered, 

 except the slightly but distinctly smaller size of simplex. 



A rare species, unrecorded from Scotland and Ireland. Has been 

 found in several localities in England and Wales, always on Natterer's 

 bat (Myotis nattereri), apparently its only host. 



43. ISCHNOPSYLLUS HEXACTENUS KoUn. (1856). 



(Fig. 90). 

 With six combs. 



(J . Apical area of mesonotum reduced, the dorsal bristles of the 

 sub-apical row long. Eight sternite short and curved, with a number 

 of long and slender bristles. Both bristles of the clasper stout, and 

 about as long as the finger (fig. 90). The latter shaped like a sock, 

 vrith the toes pointing distad, the bristle placed at the distal angle 

 being stronger and longer than the other bristles of the finger. 



$ . Seventh sternite with about five bristles on each side, besides 

 one or two small hairs. Stylet 3 times as long as it is broad. 



A common species in England and Ireland, but not recorded from 

 Scotland. The chief host is the long-eared bat {Plecotus auritus) , but 

 specimens have been found on other species of bats. 



Ischnopsyllusi unipectinata Taschenb. (1880) occurs commonly on 

 the Continent on the horse-shoe bats (JRhinolopJius ferrum-equinum and 

 B. hijjposideros), but has, so far, not been found in the British Islands. 

 The rarer species of bats in Grz-eat Britain, such as the hairy-armed 

 bat (Nyctalus leisleri), Daubenton's bat {Myotis daubentoni), and the 

 whiskered bat {Myotis mystacimis) , as well as the barbastelle (Barba- 

 stella barbadeUus) would probably yield species of fleas new to Britain, 

 if a larger number of specimens were carefully examined. 



The larvae of bat fleas live in the dung of the bats, and if 

 the same is placed in a suitable receptacle, such as a wooden box with 

 a glass lid, the fleas can be easily brought to maturity. 



