286 
Hermaphroditism etc. in Pediculus 
Systematic Description of 32 Hermaphrodites: Material (a) and (b). 
To facilitate the description of our 32 specimens, we have arranged them 
in groups as follows: 
Group I. With posterior end of abdomen rounded as in the normal d, 
with d and $ genitalia present and having the general appearance of a male 
as indicated by the sign 
(a) With d and $ genitalia equally well developed except for the 
posterior abdominal lobes of $. 
( b) With d genitalia complete but with $ genitalia reduced and in- 
vaginated in the median line. 
(c) With d genitalia complete, the ? genitalia being represented by a 
unilateral gonopodial invagination. 
(N.B. Specimens 95, 96, 118, 119, 149, hereinafter described, see pp. 301, 
304, 307, represent an intermediate Group between Groups I and II.) 
Group II. With posterior end of abdomen bilobed as in the $. With 
$ genitalia well developed, d genitalia obsolete or much reduced and enclosed 
in the body. Having the general appearance of a $ as indicated by the sign 
Group I (18 § specimens). 
(a) With d and $ genitalia equally well developed except for the posterior 
abdominal lobes of $. 
SPECIMEN 1, f PI. XV, fig. 1; PI. XVII, fig. 4. 
Dorsal bands complete. Legs: pair I as in normal d, pair III as in normal $. 
d genitalia abnormal, with basal plate and dilator (dil.) flattened, very wide, 
asymmetric, with point curved to the left side of the insect. $ genitalia 
consisting of almost normal gonopods ( gon .), the right gonopod slightly 
smaller. d ventral plate ( v.pl . d) well chitinized and divided (bipartite) in 
two widely separated pieces of irregular form. $ ventral plate {v.pl. $) rhom- 
boidal, totally separated from the foregoing. Two very small rudimentary 
$ posterior lobes (PI. XVII, fig. 4) bearing sensory hairs and situate dorsally 
flanking the anus. Abdominal muscles: dorsally as in d> ventrally as in $; 
no other internal organs visible. 
SPECIMEN 2, f PI. XV, fig. 2; PI. XVII, fig. 6. 
Dorsal bands slightly fragmented. Legs: pair I as in d, pair III as in $. 
d genitalia abnormal, with basal plate and dilator distorted, the dilator with 
penis protruding out of the body and curved to the left side. ? genitalia 
consisting of two normal gonopods. d ventral plate bipartite, the left portion 
being fused to the $ ventral plate, the plates being of irregular form. Posterior 
end of abdomen obliquely truncated. Two rudimentary $ posterior lobes 
(p.l., PL XVII, fig. 6) are visible dorsally. The specimen had the vagina and 
