16 PROCEEDINGS OF THE NATIONAL MUSEUM vol. n 



5. Prothorax specialized almost entirely by its great breadth. 



6. Same as in Dennyus and Eureum. 



7. No patches of setae on posterior femora or on some of abdomi- 

 nal sternites. 



8. Same as in Dennyus and Eureum. 



9. No evidence of any incipient segmentation of the tibia. 

 Hirundoecus thus has two only of the four important primitive 



characters listed for Dennyus and Eureum. Of the nine specialized 

 characters of Dennyus and Eureum., Hirundoecus has three of the 

 same kind. Of the remaining six specialized characters, Hirun- 

 doecus is without three, it has two that are less specialized or devel- 

 oped than in Dennyus and Eureum and one that is more specialized. 

 Hirundoecus., therefore, is not to be regarded as of such an ancient 

 type as Dennyus or Eureum., also it is not a genus as highly special- 

 ized. It is decidedly more in line with the prevailing types of 

 Menoponidae than ' is Dennyus and Eureum notwithstanding the 

 unusual shape of the body. 



BEARING ON PIOST PHYLOGENY 



Our data are not sufficient to enable us to present much that is of 

 value bearing on host phylogeny. It appears, however, that the 

 Amblycerous Mallophaga of swifts and swallows instead of being 

 closely related and belonging to the same genera should be placed, 

 on morphological grounds alone, into widely separated genera. 



The swift-infesting genera Dennyus Neumann and Eureum Nitzsch 

 are not related to the hummingbird-infesting genus Trochiloecetes 

 Paine and Mann. Trochiloecetes belongs to a different family, the 

 Ricinidae, which should include lice almost, if not entirely, from 

 passerines and hummingbirds. 



A study of the Ischnoceran Mallophaga of sv*^allows may throw 

 some light on the problem of host and parasite phylogeny. 



LIST OF REFERENCES 

 Denny, H. 



1842. Monographia Anopliirorum Britanniae, 262 pp., 26 pis. 

 Ferkis, G. F. 



1916. Some Generic Groups in the Mallophagan Family Menoponidae. Can. 

 Bnt., vol. 68, pp. 301-311, figs. 10-15. 

 Hakeison, L. 



1916. The Genera and Species of Mallophaga. Parasitology, vol. 9, pp. 

 1-156. 

 Peters, H. S. 



1928. Mallophaga from Ohio Birds. Ohio Jour. Sci., vol. 28, No. 4, pp.. 

 215-228. 



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