154 



ON THE MALLOPHAGAN FAMILY TRIMENOPONIDAE ; WITH A 

 DESCRIPTION OF A NEW GENUS AND SPECIES FROM AN AMERICAN 



MARSUPIAL. 



By Launcelot Harrison, B.Sc, B.A. 



Zoology Department, University of Sydney. 



With 2 Figures in the Text. 



Mallophaga from Australian Marsupials have been known for many years, 

 the first having been- described by Piaget in 1880, but hitherto no species has 

 been recorded from an American marsupial. In May, 1919, I was permitted, 

 through the kindness of Mr. Oldfield Thomas, to examine skins of some of these 

 latter animals in the collection of the British Museum (Natural History) ; and 

 was successful in obtaining from two species of Peramys a number of indivi- 

 duals of a Mallophagan species, which proved to be new and curiously interesting. 



Mallophaga from Australian marsupials are contained in a family, the Boo- 

 pidae, which finds its closest relations in the Gyropidae, a family found upon 

 certain South American rodents. Certain South American rodents also harbour 

 the two contained species of a third family, the Trimenoponidae. With the ex- 

 ception of these three small groups, all mammalian Mallophaga belong to the 

 widely different family Trichodectidae, which is placed in a distinct super- 

 family. 



Believing as I do that Mallophagan parasites afford valuable indications as 

 to the genetic relationships of their hosts, I have always been puzzled by this 

 distribution. That the marsupials of Australia should not carry the same kinds 

 of parasites as the Eutherian mammals is reasonable enough. But, apart from 

 marsupials, I should have expected all other mammalian Mallophaga to belong 

 to the Trichodectidae. Hence the occurrence of two small, but distinct, families, 

 not upon rodents in general, nor even upon American rodents in general, but 

 on a limited number of South American rodent species, families which showed, 

 moreover, some relationship with the Boopidae, but differed from all other 

 Mallophaga, was difficult to reconcile with my ideas. 



The explanation would appear to be that such Amblyceran Mallophaga as 

 occur on South American rodents have been migrants in the past from the 

 marsupial stock. The new genus which I describe from a South American mar- 

 supial must be placed in the Trimenoponidae, but shows some marked features 

 of resemblance to the Boopidae, and some points of contact with the Gyropidae. 

 It is, of course, no use trying to base definite conclusions on a single niarsupial- 

 infesting species, but it seems likely that, when more information is available 

 concerning the Mallophagan parasites of American rodents and marsupials, the 

 suggestion thrown out here may be upheld. It is also possible that the dis- 

 covery of further connecting forms will make it advisable to unite these three 

 anomalous groups under one family name. 



