OF WASHINGTON. 399 



dog harbors one stage of the peculiar degraded parasites of the 

 order Linguatulida, the othei stages of which are passed upon 

 herbivorous animals. Domestic herbivorous animals, as every 

 one knows, are extremely subject to the attacks of parasites, bot 

 flies, Hippoboscidae, Pediculidas, and Mallophaga combining to 

 annoy them and affect their health, while many species have their 

 own particular species in one or more of these groups. 



The Elephant supports an interesting species of true louse of 

 very peculiar structure, possessing a long proboscis, necessitated 

 by the thick skin of the host. One or more mites are also found 

 upon this animal. Bats are affected by a peculiar group of Dip- 

 tera which have been separated into a family by themselves (Nyc- 

 teribiidae). The Insectivora are moderately free from parasites, 

 but rodents are badly infested. House mice, though ordinarily 

 free from lice, are generally attacked by mites. Field mice and 

 rats, however, have lice peculiar to them, and are also affected by 

 mites and fleas. Squirrels and rabbits are affected by lice and by 

 bot-flies of the genus Cuterebra. The beaver is but moderately 

 affected by mites and Mallophaga, but has a peculiar parasite of its 

 own, that aberrant beetle which forms the type of the Platypsyllidae. 

 The Edentata and the Marsupials are singularly free from parasites, 

 and this fact would seem to indicate that their practical isolation in 

 Australasia had taken place before the present forms of parasitic 

 insects had evolved. 



Birds are almost universally infested with parasites of many 

 different kinds. They are peculiarly subject to the attacks of Mal 

 lophaga, which are, for this reason, ordinarily known as bird- 

 lice. Some true lice and some Hippoboscids also affect birds, 

 while fleas of various species add to the list. 



Very few records of insect parasitism upon Reptilia exist, and 

 none upon fishes. Among the reptiles, turtles are know to be 

 parasitized, while Brauer has shown that Uperolaia marmorata 

 and Cystignathus sydneyensis are infested in New South Wales 

 by Batrachomyia. Dr. Packard has recorded and figured a 

 genuine CEstrid larva taken from under the skin of the back of 

 the neck of the Box Turtle ( Cistudo Carolina]. Mr. F. W. True 

 has mentioned another case of the same sort, while I have received 

 a Lucilia larva taken in Indiana from beneath the skin of n turtle, 

 between the hind legs. 



