KEY TO GENERA OF ANOPLURA 



543 



Antennae five- jointed . . . . '. . . . Pediculinae 8 



8. Forelegs slender, with very long and thin claws. The other 



legs very strong with short thick claws. Thumb-like 

 process of the tibia short and strong. Abdomen very short 

 and broad. First to fifth_abdominal segments strongly com- 

 pressed, so that the stigmata of the third to fifth segments 

 lie apparently in one segment. Fifth to eighth segments 

 with lateral hook-like processes, the penultimate one long, 

 the last very long. The two-jointed telson on each side 

 without cone-shaped process. Gonopodia of the female 



triangular . ... Phthirus. 



All the legs strong. Thumb-like process of the tibia very long 

 and thin, covered with strong bristles. Forelegs a little 

 more compact and stronger than the rest. Abdomen 

 elongated, moderately narrow, the segments not compressed 

 together ; without lateral hook-shaped process. The two- 

 jointed telson bears on the under surface posteriorly a cone- 

 shaped process on each side. Gonopodia of the female 

 clamp-like and bent inwards ....... Pediculus. 



9. Antennae with three joints Euhaematopininae 16 



Antennae with five joints ........... 1 



10. Forelegs the same size and thickness as the others. Eyes rudi- 



mentary, situated at the point of a forwardly directed fork- 

 like lateral process of the posterior part of the head. A tri- 

 angular sclerite between tarsus and the tibia (pretarsal- 



sclerite). Mandible well developed and two-jointed . Haematopiuinae I I 



Forelegs more slender than the rest. Eyes wanting. Hinder 

 part of the head smooth, without lateral forked process. 

 Mandibles rudimentary. No sclerite between the tibia and 

 tarsus .."',.. *" Linognathinae 12 



11. Thorax and abdomen broad. Third to eighth abdominal 



segments with chitinized thickenings of the pleura, irregularly 

 bordered, expanded a little outwards, and so giving to the 

 lateral margin a wavy appearance. On each tergite up to the 

 sixth an indistinct, irregular, and rather sharply defined 

 plate, which is wanting in some species. Each abdominal 

 segment bears a transverse row of minute hairs, usually 

 widely separated from one another ..... Haematopinus. 



12. Abdomen with strongly chitinized tergite, sternite, and pleurite ; 



tergite and sternite partly secondarily divided. Abdominal 

 border appears serrated on account of extension of the pleura 

 backwards and outwards. Hind leg stronger than the middle 

 leg. Claw of the hind leg short and much compressed, and 

 can be fitted into the tarsus ............. I* 



Abdomen without sclerites and plates. Border of abdomen 



smooth. Hind leg the same size as the middle leg . . . . 14 



13. Abdomen elongated. Fourth to seventh sternites and second 



to seventh tergites divided each into two plates lying one 

 behind the other. Each of these plates with a transverse 

 row of long and strong hairs. Pleura without serrated 

 process on the inner side. Stigmata small . * .'. ; .';. . Polyplax. 



