D. Keilin and Gr. H. F. Nuttall 
301 
No. 83 (Text-fig. 17), a very dark specimen. Dorsal bands normal, as in 
the d- Legs: pair I as in <£, pair III as in $. $ genitalia extruded as in copula¬ 
tion, of very peculiar structure; the vesica penis bilobed, each lobe being 
connected with a lateral portion of the dilator, which, instead of ending- in 
a point, consists of two widely separated rami (resembling somewhat No. 53). 
The statumen penis is duplicated, but the penis is absent. The ventral 
plate is divided in two pieces between which occurs a very dark chitinous 
invagination representing rudimentary $ genitalia. 
The hermaphroditic characters of this group (b) consist of fragmented 
dorsal bands, the $ structure of leg III, the presence of a $ ventral plate 
though deformed and invaginated, internal chitinous invaginations with 
sensory hairs, and various forms of prolapsed vagina. In a few examples of 
groups (a) and (b) we observe two very small supplementary chitinized plates 
Text-fig. 17. Pediculus humanus, cross between capitis and corporis. Specimen 83, f, showing 
posterior end of abdomen, dorsal aspect, with protruded double vesica penis ( v.pcn .), dilator 
(dil.), posterior abdominal lobes (p.l.), statumen penis ( st.pen .). (K. & N. del.) 
situate ventrally in the segment anterior to that which normally bears the 
ventral plate (No. 84, see Text-fig. 16 d). 
(c) SPECIMENS 95-96 of intermediate type between ^ and 
No. 95 (Text-fig. 16 a and b) has the dorsal bands slightly fragmented, 
leg I as in d, leg III as in $. The posterior end of abdomen asymmetrical 
and of intermediate type with abdominal lobes much reduced. $ ventral 
plate consists of two widely separated pieces. $ ventral plate of annular 
form, surrounding a gonopod with its basal portion. $ genitalia with basal 
plate, dilator, vesica penis, and statumen penis, all reduced, deformed, and 
completely enclosed in the last abdominal segment. 
