CLASSIFICATION 541 



segment may bear more or less conspicuous eminences, projecting from 

 the end of the body. Anterior to these are two lateral elevations or 

 thickenings in the chitin, the gonopodia, which may be small and 

 inconspicuous, or large. The genital aperture lies between these two 

 pairs of structures. The shape and vestiture of these parts provide 

 important taxonomic characters ; usually each is provided with a row of 

 bristles, which may be very conspicuous. 



The integument of the louse is of a tough and leathery consistence, 

 and is strengthened by a deposit of chitin at certain points, such as the 

 lateral borders, and in parts of the head. As a rule it is not heavily 

 pigmented, and the mid-gut can be seen through it when the latter contains 

 the usual black residue of blood. The vestiture consists of hairs and 

 bristles of varying length and size, arranged for the most part in trans- 

 verse rows on the tergites and sternites ; the hairs are usually longer on 

 the posterior segments than on the anterior, and are recumbent and 

 directed backwards. 



CLASSIFICATION AND DESCRIPTION OF IMPORTANT 



FORMS 



The following classification of the Anoplura is that adopted by 

 Enderlein, who recognizes four families, including in all fifteen genera. 

 Fam. PEDICULIDAE, Leach. 



Sub-Fam. PEDICULINAE, Enderlein. 

 Genus PEDICULUS, L. 



PHTHIRUS, Leach. 

 Sub-Fam. PEDICININAE, Enderlein. 



Genus PEDICINUS, Gervais. 

 Fam. HAEMATOPINIDAE, Enderlein. 



Sub-Fam. HAEMATOPININAE, Enderlein. 



Genus HAEMATOPINUS, Leach. 

 Sub-Fam. LINOGNATHINAE, Enderlein. 

 Genus LINOGNATHUS, Enderlein. 

 ,, POLYPLAX, Enderlein. 

 ,, HOPLOPLEURA, Enderlein. 

 ,, HAEMODIPSUS, Enderlein. 

 ,, SOLENOPOTES, Enderlein. 

 Sub-Fam. EUHAEMATOPININAE, Enderlein. 

 Genus HAEMATOPINOIDES, Osborn. 

 EUHAEMATOPINUS, Osborn. 



