142 MODERN SYSTEM. 



placed in an order which he named Purasifu. This name Dr. Leach 

 has changed for the sake of harmony, and also to render the name 

 more easy of retention in the memory, the characters being drawn 

 from the same ])arts. 



Tiieir motion is slow, and their nourishment is derived from the 

 blood of mammalia, birds and insects. 



" It is almost an established fact, that every species of bird (and 

 probal)h' mammiferous animal) has its own peculiar parasite; and 

 there is no instance of the same species of louse having been ob- 

 served on two distinct species of birds, although some l)irds (as the 

 raven oyster-catcher, Sec.) are infested with several ppecics of para- 

 sites." The importance of clearly ascertaining the truth is such to 

 the ornithologist, that Dr. Leach has employed a considerable por- 

 tion of time ibr the purpose of investigating and of describing the 

 species with accuracy, little more than a bare catalogue of names 

 and habitats having been given in the works of Linne, Fabricius, 

 and Gmelin. The result of his examinations he does not consider* 

 himself as able to communicate at present; but it is his intention, 

 when the subject has arrived at maturity, to give a paper on this Or- 

 der to the Linnean Society of London. 



Fam. L PEDicui.iDiE. Leach. 

 Mouth consisting of atubulose, very short haustellum. 



Genus 6. PHTHIRUS. Leach. Petjiculus. Linn., Red}, Lair., 



Fabr. 

 Anterior pair of feet simple; two hinder pair didactyle : ^//ora.r extremely 



short, scarcely visible. 

 Sp. 1. Phth. inguinalis. Body whitish. 

 Pediculus inguinalis. Redi. Pediculus pubis. Linn., Fair., Latr. Le 



Morpion. Ccoff. Phthirus inguinalis. Leach. 

 Inlmbits the eyebrows, &c. of men and women, being commonly 

 known under the titles Crabs, Crab-lice, Sec. 



Genus 7. PEDICULUS. Linn., Fair., De Gcer, Geoff., Redi, 

 Hermann, Lam., Leach. 

 Feft all armed \vith a finger and thumb: thorav composed of three di- 

 stinct equal segments. 

 Sp. 1. Ped. humanus. Body oval, lobate, white and nearly immaculate. 

 Pediculus humanus. Fabr., Linn., Latr., Leach. 



Inhabits the bodies and garments of men, and is known by the name 

 of the body-louse. On the continent of Europe, especially in Spain 

 and Portugal, it is very abundant. In Britain it is of rare occur- 

 rence, and may have been introduced from the neighbouring coun- 

 tries. 



