Ixodes putus and vespertilionis are solely parasites of birds and bats, 

 although putus may occasionally attack man when he approaches the 

 infested birds' nests. 



With the exception of /. hexagonus 1 , including var. cookei, of which 

 we have no particulars, the males of these species have never, apparently, 

 been captured upon the host. On the other hand, the males of the other 

 species have been found in the habitats of their hosts: canisuga in the 

 nests of sand-martins (bank-swallows) and in a dog kennel, vespertilionis 

 in caves inhabited by bats, putus in and about the nests of marine birds. 

 In such localities the males would have ample opportunities of feeding 

 upon their hosts for brief periods after the manner of male Argasidae, 

 assuming that they do feed. It is conceivable, however, that such 

 habitat-infesting males may not be blood-suckers at all. We have seen 

 that Ornithodorus megnini £ does not feed, and that it nevertheless 

 fertilizes the female. The same may hold for certain Ixodidae r/s. 

 The matter requires further investigation. The sexes of canisuga and 

 putus have often been observed in copula apart from the host, and it 

 appears probable that this is the usual occurrence in nature 1 . 



List III (p. 341) is likewise very striking. It includes all the 

 species (26) of which the males are still unknown. With the exception 

 of three species (bicornis, stilesi and australiensis), all of the females 

 have been found solely on birds, burrowing or nesting hosts, and bats. 

 Of /. bicornis only three females are known ; they were found on 

 as many hosts. Ixodes stilesi has only been found once, and all the 

 specimens (14 females) were found upon a single host. Ixodes austra- 

 liensis was found once on a dog (+), and once on the marsupial rat- 

 kangaroo (0). It is true that many of the species are represented only 

 by one or two females, or by few specimens, and consequently there 

 may be an error in certain cases in attaching much importance to the 

 character of the type host — nevertheless, there is a very remarkable 

 co-relation between the absence of males on the host and the life habits 



of the host. 



1 See note on p. 345. 



