FLEAS 115 



THE HOUSE-SPARROW FLEA, C, fringUlae (Plate XIV, XV). This 

 species is small and pale and gives an impression of delicacy. It is a 

 parasite of the house sparrow, not of finches as its name suggests. 

 Sometimes it is found as a straggler in the nests of other small birds and 

 it has been recorded from the skylark, great tit and pied wagtail. On 

 the other hand its presence in the empty nests of starlings, house- 

 martins, swallows and swifts is no doubt due to the true host's habit of 

 usurping other birds' nests. When the house-sparrow was introduced 

 into the United States C, fringUlae was either left behind or failed to 

 establish itself in the new surroundings, for up till now it has not been 

 recorded in North America. 



The eighth sternite of the male and receptaculum seminis of the 

 female are quite distinct, but this species is frequently mistaken for the 

 hen flea (C. gallinae) and published records have, therefore, to be 

 treated with caution. 



THE VAGABOND FLEA, C vdgabunda (Plate XIV, XV). This is 

 a relatively rare flea found in Britain in the nests of the jackdaw and 

 rock-dwelling sea birds such as the herring-gull, kittiwake and the shag. 

 It is apt to wander on to other cliff-dwelling birds and has been recorded 

 from the peregrine falcon and the rare honey-buzzard in Cornwall and 

 the raven in Ireland. Inland it has been found only three times apart 

 from the five records off the jackdaw which are discussed in the section 

 on distribution. Nests of this bird are easy to collect and it would be of 

 great interest to see how widely spread C. vagabunda is on the mainland 

 of Britain. It is well established on jackdaws around Oundle and in 

 such widely distant localities as Herefordshire, Cornwall and Mid- 

 lothian. 



As we have already noted on p. 87 this flea has broken up into 

 subspecies, and the British representative, Ceratophyllus vagabunda 

 insularis, is peculiar to these Islands. 



THE SHEARWATER FLEA, Omithopsylla laetUiae (Plate XI, XIII, 

 XVI, XXXIII and Map 4) . This is the only Pulicid bird flea inBritain 

 and shares with Orneacus rothschildi the distinction of being peculiar to our 

 fauna. A glance at Plate XVII will show what a contrast this species 

 presents with any of our other bird fleas. It is relatively compact, short 



FFC— I 



