106 THE FLEA [CH. 



The fleas found on bats possess certain peculiari- 

 ties which have led to their being grouped together. 

 They form a family to which the name Ceratopsyllidde 

 has been given. They are recognized by two flaps, 

 one on each side of the head. What these are and 

 what service, if any, they render to their possessors 

 is unknown. Bat-fleas also, as a rule, have maxillae 

 shaped like dumb-bells ; but in one genus (Thau- 

 mopsylla\ found on fruit-bats, they are triangular 

 as in other fleas. The maxillae, as the reader may 

 remember, are parts of the insect's mouth, and, 

 though placed like jaws on each side of the aperture, 

 they are not used in piercing the skin and sucking 

 blood (Fig. 4). They bear feelers called the maxillary 

 palpi. The flea (Thaumopsylla breviceps) which is 

 found on South African fruit-bats and which has 

 triangular maxillae, seems to be a connecting link 

 between this peculiar group of fleas and the main 

 family Pulicidce. 



Bat-fleas are commonly well supplied with combs. 

 They usually have them on the abdomen, as well as 

 the head, and the maximum number of eight combs 

 is found in bat-fleas. Their structure and life-history 

 agree generally with that of other fleas. They breed 

 in hollow trees, caves, ruins, church-towers and lofts 

 where bats hibernate or spend the hours of daylight. 

 The larvae feed on the droppings of the bats, and the 

 mature insect, after emerging from the pupa case, 



