of certain Hymenopterous Insects. 409 
The remaining nine segments appertain to the abdominal 
region, whereof seven are furnished with a spiracle on 
either side ; the last three segments, like the five anterior, 
being firmly united together. 
By comparing these pseudo-pnpfe of smallest and largest 
dimensions, as well as those occupying the extreme cells 
of a long serial sequence (representing males and females), 
the number of segments and their conformation as afore- 
said are precisely identical. But on the development of 
the true pup^, these three conjoined segments give rise to 
the additional abdominal segment and bivalved sexual 
organs in the male (Burm. § 152) ; which segments are 
wholly absorbed in the corresponding threefold organs 
of the female, comprising also the aculeus (1. c. § 143). 
Thus Shuckard's remark (in the aforesaid note), " iliat 
the larvcB of the males in the aculeate Hymenoptera will 
necessarily have an additional segment" does not coincide 
with these results. 
The imago Raphiglossa are accustomed to repose for 
the night in a very peculiar position, the conditions of rest 
being best provided for by affixing their poAverful man- 
dibles to some rough projecting edge of the briar and then 
distending their body and legs horizontally, without other 
support than the twisting of the wings lengthwise beneath 
the abdomen, which are retained in position by the poste- 
rior legs, although even this process is frequently dispensed 
with. 
This gymnastic feat is accomplished as follows : — After 
resting awhile on a projecting snag, the Rajyldglossa drew 
back, laying firmly hold of the snag with its mandibles, 
leaving its body and the four posterior legs quite free from 
the briar. Then by a rapid movement curving the wings 
down longitudinally on either side beneath the abdomen, 
and projecting the two posterior legs as it were to retain 
the wings thus in position, the tarsi remaining free, and 
bending the abdomen downwards, it took up its position 
for the night, the intermediate legs remaining suspended, 
but the knees of all doubled up close ; now and then 
raising the abdomen without thereby disturbing the wings, 
which remained closely doubled down independently of 
such movement. The antennae were laid back on either 
side of the head, the mandibles forming the sole means of 
support, the forelegs being also doubled up close to the 
thorax and the tarsi turned back out of the way ; the body 
