Hymenopterous genus Scleroderma. 119 
parts, namely, the two outer sheaths (fig. 9 a, a, which 
appear to be coalesced along the greater portion of their 
length, and a*a* the same more magnified), and the 
ovipositor proper composed of its two spicule (fig. dd), 
dilated, much curved at their bases (figs. 9 b, 10 b), which 
are capable of protrusion from the extremity of the tubular 
horny terebra (fig. c), but which are retained from being 
too much protruded, by the two muscular angulated dila- 
tations (fig. ff.) In fig. 9 these organs are laterally 
compressed, the ovipositor being thrown out of its usual 
position, when its tip (fig. d) is generally seen at rest 
between the extremities of the two outer sheaths (fig. a a). 
In fig. 10 the parts of the ovipositor itself are vertically 
compressed, the recurved bases of the spicule (fig. ¢), 
with their muscular angulated lobe or catch (fig. ff), being 
represented as flattened. By strong protrusion of the 
spicule beyond the extremity of the terebra, the curved 
basal portions of the former are straightened, and brought 
forward to the base of the terebra, where their dilated 
angular form prevents them from further protrusion. 
The parts marked e,e in fig. 10 are the membranous 
plates connecting the base of the spiculz and of the tere- 
bra itself with the interior of the abdomen. Fig. 17 repre- 
sents the extremity of the abdomen of a female in which 
the spicule have been protruded unequally in dying. 
The external organs of generation of the males of 
Scleroderma (Plate V., fig. 8, from S. cylindrica, male) 
are very complicated, and as they are generally more 
or less exserted, may be mistaken for those of the female 
without a careful examination. They consist of two 
acute but very slender chitinous central parts or blades, 
the extremities of which are very thin and incurved; and 
two broad composite lateral pieces each with a broad 
simple stipes and four terminal lobes, two of which are 
setose at the tips, and one at least more rigid than the 
other parts. 
The wings of the males in this genus are fringed with 
fine hairs, and are almost destitute of veins, which are 
confined to the base of the anterior pair (Plate IV., fig. 11, 
basal portion of the wings of S. ephippium) ; they have 
a short subcostal vein, a shorter median or discoidal 
one united to the former at its extremity by an oblique 
vein, which is continued at an angle backwards into the 
disk of the wing; there is also a nearly obsolete subanal 
vein, of which the base is thickened, and there is an 
