Gf. H. F. Nutt all 
137 
Until recently, owing to the war, most of Fahrenholz’s publications herein 
referred to were rendered inaccessible to me, otherwise their consideration 
would necessarily have been included in my previous paper ( Parasitology , 
xi. 329-346). 
The subject-matter that follows has been arranged by me in three sections 
dealing with (1) Fahrenholz’s descriptions of supposedly new species, etc., 
(2) my detailed criticism thereon, and (3) my conclusions therefrom in respect 
to the synonymy of Pediculus humanus. 
I. 
FAHRENHOLZ’S EVIDENCE IN SUPPORT OF THE VALIDITY OF 
HIS SPECIES, SUB-SPECIES AND VARIETIES OF PEDICULUS . 
In considering the forms described by Fahrenholz, it appears convenient 
to class them in two groups : 
(a) Lice derived from man. 
Pediculus humanus race corporis (mihi). 
P. nigritarum Fabricius 1805. Regarded by Fahrenholz as a variety 
(1915) and subsequently as a sub-species (1916). 
P. humanus chinensis Fahrenholz 1916. A sub-species. 
P. humanus marginatus (Fahrenholz 1915) Fahrenholz 1916. A sub¬ 
species. 
“P. humanus humanus L.” of Fahrenholz 1917. A sub-species. 
Pediculus humanus race capitis (mihi). 
P. capitis angustus (Fahrenholz 1915) Fahrenholz 1916. A sub-species. 
P. capitis maculatus (Fahrenholz 1915) Fahrenholz 1916. A sub¬ 
species. 
U P. capitis capitis de Geer” of Fahrenholz 1917. A sub-species. 
(b) Lice derived from apes and monkeys. 
P. schaffi Fahrenholz 1910. 
P. oblongus Fahrenholz 1913, subsequently renamed assimilis (see 
below). 
P. friedenthali Fahrenholz 1916. 
P. lobatus Fahrenholz 1916. 
P. assimilis Fahrenholz 1919 ( = oblongus renamed). 
(a) Lice derived from man. 
In support of his contention that the lice occurring on various races of 
man constitute distinct sub-species, Fahrenholz (1915, p. 591 et seq.) cites 
Fabricius (1805), Olfers (1816), Denny (1842), Pouchet (1841, pp. 204-5, 
