28 



REPORT lOS^ U. S. DEPARTMEXT OF AGRICULTURE. 



Fig 



CheyletieZla canadensis. (Original.) 



TjTogh-phids among cabbage seed. Several tropical species are found with scale 



insects, and doul^tless feed on them. 



Cheletia Haller differs only in having broad, scalelike hairs on the body and legs, 



making them Yery beautiful objects when seen under the microscope. Some of the 



species also feed on scale insects, and one such 

 occurs in the "West Indies. Cheletoides and 

 Cheletopsis (fig. 28) are elongate mites that 

 live within the quills of the feathers of birds. 

 Some species have also been found outside 

 the quills; doubtless all come outside at cer- 

 tain times, at least to breed. They are sup- 

 posed to fee4 on the analgesid mites that 

 occur with them in the quills, and to which 

 they bear much resemblance. 



Dr. Oudemans, who has written a re\dsion 

 of the Cheyletinse of the world, has described 

 many new species from foreign countries. 

 He adopted 17 genera, several of wliich are 

 known from but one species. For Cheyletus 

 he uses the spelling Cheletes. 



For Earpyrynchus he proposes a new 

 name, Sarcohorus, as there was an earlier Har- 



porynchus; but the latter does not exactly preoccupy the acarian genus; moreover 



there is a Sarcopterinus Railiiet 1893 which would be available. His genus Cheleto- 



morpha differs from Cheyletus in the presence of an eye-spot each side on the dorsal 



shield, while Cheletophanes is a similar form with a peculiar 



sculptiure to the posterior part of the body. Cheletomimus 



is about the same as Cheyletia, but the posterior dorsal 



shield is di^dded, and there are not so many scalelike hairs. 



Cheletogenes is also similar to Cheyletia but with roughened 



shields. Chelenotus, I have united to Acaropsis, and Che- 



letosoma to Cheletopsis. 



Cheyletiella (fig. 27) includes several species in which the 



palpi are not as large as in Cheyletus. They usually occur 



on birds, where they feed on the other mites present and 



have been called auxiliar}'' parasites. One species, C. 



parasitivorax Mich., uses the rabbit's fur as a hunting 



forest, where it destroys the Listrophorus mites which 



occur on the hairs of the rabbit. One species (on a blue- 

 bird) has been recorded from this country. Harpyrynchus 



(formerly Sarcopterus) is represented by a few species 



that have a ver^'' short, broad body, with very short legs, 



the hind pairs ending in a bunch of bristles. They occur 



in the hair follicles of several birds, where they form 



tumors. The eggs are very large for the size of the mite. 



One species, H. longipilus Banks (figs. 29, 30) has been 



taken in the United States in a tumor under the wing of 



a crossbill. The genus Psorergaies (fig. 31) was described 



by Tyrrell from Canada. It lives parasitically on tlie 



house mouse and field mouse, in cavities, or little cells, 



just beneath the surface of the skin. It has a nearly 



round body, with very short, stout legs, each ending in two stout claws. It has 



since boon found in various parts of Europe, and was described by Michael under 



the name of Goniomerus miisculiiius Mich. 



Fig. 29..— Cheletopsis nvmeri. 

 (Original.) 



