f 



c d 



Photographs by Arthur L. E. Barron 



The shearwater flea, a, Ornithopsylla laetitiae (male, x 17), is related to the rabbit flea, 

 b, Spilopsyllus cuniculi (male, x' 22), whereas the hen flea, c, Ceratophyllus gallmae 

 (male, /' 19), is probably derived from a rodent flea similar to d, Ceratophyllus anisus 



(male, x 20) 



Plate XI 



