8 NORTH AMERICAN ANOPLURA 



Legs all of same size . . Subfamily Haematopininae 



(One genus, Haematopinus) 



12. Anterior pair of legs with two claws . . . Genus Scipio 

 Anterior legs with but one claw 13 



13. Abdomen with well developed pleural plates ....... 16 



Abdomen entirely without pleural plates 14 



14. Abdominal spiracles large, tubular, projecting from 



the body-wall Genus Solenopotes 



Abdominal spiracles small, not projecting from the 



body-wall 15 



15. Head usually slender, but little widened behind the an- 



tennae, gonapods of female long, frequently 



reaching beyond the extremity of the body; for 



the most part infesting Ungulates 



Genus Linognathus 



Head broad, considerably widened behind the antennae, 



gonapods very short; infesting rabbits . . . 



One species of the Genus Haemodipsus 



x6. Tergites and sternites of the abdomen for the most 



part with more than one transverse row of hairs .... 19 

 Tergites and sternites of the abdomen for the most 



part with but one row of spines 17 



17. Middle and posterior pairs of legs of equal size, larger 



and stouter than the anterior pair 18 



Anterior and middle pairs of legs of the same size, 



smaller than the posterior pair . Genus Enderleinellus 



18. Abdomen with a pair of chitinized plates on the sec- 



ond sternite . Genus Fahrenholzia 



Abdomen without such plates 



Genus Haemodipsus (in part) 



19. Abdominal tergites and sternites with not more than 



two rows of hairs 20 



Abdominal tergites and sternites in part with three 



rows of hairs Genus Hoplopleura 



20. First antennal joint with a stout spine at the distal 



postaxial angle or on the posterior margin . . 



Genus Neo haematopinus 



First antennal joint not so 21 



21. Abdominal tergites and sternites with distinct chitin- 



ized plates Genus Polyplax 



Abdominal tergites and sternites without distinct chi- 

 tinized plates Genus Linognathoides 



