D. Keilin AND Gr. H. F. Nuttall 
289 
and more chitinized. $ genitalia with gonopods of very unequal structure 
and size; the right gonopod is small, but of normal structure; the left gonopod 
(gon.l.) is larger and deformed as follows: the major portion forms a gutter¬ 
like depression along whose borders are ranged sensory hairs with their 
apices directed into the gutter; alongside the gutter, but nearer the median 
line, occurs a pointed protuberance bearing sensory hairs, the base of the 
protuberance overlapping the posterior portion of the gutter. Between the 
gonopods there was a vaginal prolapse ( prol .), which was cut away before 
the specimen was drawn. Dorsal and ventral abdominal muscles as in 
Internal organs: one testis and ova in various stages of development were 
observed. The posterior end of abdomen asymmetric, obliquely truncated; 
two processes bearing sensory hairs occur laterally and posterior to the 
gonopods. 
(b) With d genitalia complete but with $ genitalia reduced and invaginated 
in the median line. 
SPECIMEN 9, f PL XVII, fig. 1. 
Dorsal bands as in normal $. Legs: pair I as in <£, pair III as in $. $ 
genitalia asymmetric, especially in the anterior part of basal plate. $ ventral 
plate divided in two parts of irregular form; between these parts there is a 
deep invagination ( invag.gen .) of dark chitin forming within the body of the 
insect a very irregular mass with two lateral pockets bearing sensory hairs 
internally; these pockets may be homologized with invaginated gonopods, 
whilst the main mass of chitin corresponds to the $ ventral plate. Dorsal 
and ventral abdominal muscles as in 
SPECIMEN 10, <£. Not illustrated. 
Dorsal bands as in Legs: pair I as in <$, pair III as in $. d genitalia 
asymmetric, reduced, slightly oblique. $ ventral plate consists of two widely 
separated portions, separated by a chitinous invagination of very irregular 
shape, thickness, and colour; this invagination (as in Specimen 9) corresponds 
to different parts of the $ genitalia. Dorsal and ventral abdominal muscles 
as in <J. 
SPECIMEN 11, <£. Not illustrated. 
Dorsal bands as in slightly chitinized. Legs I and III as in S genitalia 
asymmetric, especially in respect to the dilator, which, with the penis, is 
protruded from the body (as in Specimen 1). $ ventral plate invisible, but, 
as in the two foregoing specimens, there occurs a chitinous invagination of 
very irregular form and colour. Posterior end of abdomen asymmetric. 
Dorsal and ventral abdominal muscles as in <J. Internal organs: three testes, 
two on the left side of normal size, one on the right much reduced. 
19—2 
