OF WASHINGTON. 415 



Ephemeroptera. The Neuroptera, in the more restricted sense, 

 furnish, in Mantispa, an illustration of partial parasitism, the 

 larvae feeding and developing in the egg-masses of spiders and 

 undergoing rather remarkable transformations. 



LEPIDOPTERA. Among the Lepidoptera we have a number of 

 species which are predaceous, and others which are commensals, 

 and the habits of some of these verge upon parasitism. Two 

 Lepidopterous larvag are recorded by Westwood, from Lndia, as 

 feeding upon the white waxy secretion of Aphina eurybrachis 

 and other Fulgoridae during the life of these insects, while in South 

 America a small Tineid moth is recorded as preying upon 

 Brady pus tridactylus, or the Three-toed Sloth, the larvae 

 probably feeding upon the hair of these curious mammals. A 

 similar observation has been reported concerning a Tineid larva 

 which feeds in the hair of living monkeys. We may, also, 

 safely assume that the Tineids which so increase the cares of the 

 good housekeeper have acquired their habits since man learned 

 to weave, and that they may have taken their wool, originally, in 

 its growing condition. 



The predaceous habit, when internal and confined to some 

 specific insect, borders very closely onto parasitism. Eucle- 

 mensia bassettella, in the gall-like gravid females of Kermes 

 galliformis, is a case in point ; while Chalcoela aurifera, 

 in the larva state, destroys the larva of Apis and of Polistes, 

 transforming within the cell of its host. 



PLATYPTERA. Last to be considered among the Hexapods 

 are the Bird-lice, or Mallophaga. These peculiarly modified 

 parasites are placed, according to the classification of Packard, 

 with the White Ants, Psocidae and Perlidae, in the order Platyp- 

 tera. Brauer, however, places them in the order Corrodentia. 

 They were placed by older authors among the Hemiptera, but 

 belong properly with the Psocids and Termites on morphologic 

 and embryologic grounds. The main difference in habit between 

 the bird-lice and the true lice consists in the fact that the former 

 have biting mouth-parts, while those of the latter are suctorial. 

 The parasitic habit has resulted in a hard, horny and greatly 

 flattened body, very short antennas, large and modified legs, and 

 a peculiarly shaped head, which, however, does not differ so 

 much as might be expected from the ordinary Psocid type. The 



