Akt. 19 LICE OF THE GENUS PEDICULUS EWING 7 



Also material was obtained from negroes in Africa and Caucasians 

 in Europe in order to have more assurance that the specimens 

 studied should be really representative of the type belonging natu- 

 rally to the host race on which they were found. Of course there is 

 no real assurance that in these last two instances the lice obtained were 

 typical for the race on which they were obtained, yet by checking 

 up with various other records it is believed that they are very nearly 

 typical, if no actually so. 



Bacot (1917) in his breeding experiments found that some of the 

 characters Mendelized, and, largely because of this fact, concluded 

 that the common head louse and the body louse should be considered 

 as distinct species. An examination of a large series of atypical 

 lice (hybrids) j)resents various degrees in intergradation, these de- 

 grees becoming so fine in certain instances as to simulate a blending 



of characters. 



Genus PEDICULUS Linnaeus 



1758 Pediculus Linnaeus (part), Syst. Nat., ed, 10, p. 610. 



1842 Pediculus Denny, Mon. Anop., p. 12. 



1874 Pediculus Giebel, Ins. Epizoa, p. 27. 



1880 Pediculus Piaget, Les Pediculines, p. 619. 



1904 Pediculus Enderlein, Zool. Anz., vol. 28, pp. 136 and 138. 



1908 Pediculus Dalla Torre, Gen. Insect., Anop., p. 8. 



1910 Pediculus Mjoberg, Ark. f. Zool., vol. 6, no. 13, p. 167. 



1916 Pediculus Ferris, Proc. Cal. Acad. Sci., ser. 4, vol. 6, p. 136. 



1919 Pediculus Nuttall, Parasitology, vol. 11, p. 334. 



The genus Pediculus may be described as follows: With the 

 characters of the family Pediculidae, and in addition, antennae 

 distinctly segmented ; legs all of the same size ; in the male, the 

 first pair of legs modified distally for clasping and in the female 

 the hind femur provided with a posterior tubercle. Eyes conspicu- 

 ous, pigmented. Abdomen elongate, segmentation marked; no 

 lateral protuberances; pleural plates on all segments except the first. 

 Gonopods of female conspicuous, slightly curved. Not all of the 

 body setae arranged in transverse rows. 



KEY TO SUBGENERA OF PEDICULUS 



Typical pleural plates with lateral lobes ; body setae rather inconspicuous 

 and, setiform, and nearly all of them arranged into transverse rows ; 

 thoracic spiracles not conspicuous ; chitinous parts usually heavily pigmented. 

 Living on American monlieys. 



Subgenus Parapediculus, new subgenus. 

 (Type species, P. consohrinus Piaget) 

 Typical pleural plates without lateral lobes ; body setae conspicuous, fre- 

 quently peglike and seldom over one-half of them arranged into transverse 

 rows ; thoracic spiracles large, conspicuous ; chitinous parts frequently 

 poorly pigmented. Living on man. 



Subgenus Pediculus Linnaeus. 



