HYMENOPTERA. 
307 
GerstackeR, in the introduction to his memoir on the genus 
Oxyhelus (Zeitschr. fiir die ges. Naturw. xxx. pp. 1, 2), remarks 
upon the general classification of the Hymenopteraj and indi- 
cates their division into two main groups, Hymenoptera apocrita 
or genuina and Hym. symphyta or phytophaga. These sections, 
which the Recorder has always regarded as the natural main divi- 
sions of the order Hymenoptera, are characterized, according to 
Gerstacker, by the transfer to the thorax in the former of the first 
abdominal segment, and its retention in the abdomen in the 
latter, so that in the Hym. apocrita we can never distinguish 
more than 8 dorsal half segments, whilst 9 are recognizable in 
the Hym. symphyta. The characters of the larvae, which tho- 
roughly bear out this mode of division, are too well known to need 
mention. 
Landois (Zeitschr. fiir wiss. Zool. xvii. pp. 163-167) notices 
the sounds emitted by many Insects of this order, and the appa- 
ratus by which they are produced. In the Hive-Bee (^Apis meU 
lified) a sound is produced by the vibration of the wings during 
flight ) but the true voice of the Insect is produced by the band- 
like margins of the stigmata, both thoracic and abdominal. 
These form elongated apertures. This structure occurs also in 
the other Bees, Wasps, &c. In the Bombi the metathoracic 
stigmata are also sound-organs, having the same structure as in 
the Hive-Bee. The abdominal stigmata are here the chief pro- 
ducers of sound (pi. 11. fig. 19), and they present a rather com- 
plicated construction. Each stigma is an oval aperture sur- 
rounded by a chitinous ring; it is situated beneath a hemi- 
spherical cup divided by a slit into two nearly equal parts, and is 
furnished with a double chitinous membrane stretched between 
the stigma and the lower half of the cup. It is by the vibration 
of these parts that the well-known sound of the Bombi is pro- 
duced. 
Morawitz (Horse Soc. Ent. Boss. v. pp. 39-45) gives a gene- 
ral account of the Aculeate Hymenoptera of the neighbourhood 
of St. Moritz in the Upper Engadine, followed by a list of the 
Bees of the district, Which constitute the most numerous and 
interesting group there. The Vespidae, especially the social 
forms, are very numerous in individuals ; but the Eossores are 
not strongly represented either in individuals or species. Of 
Heterogyna the author notices only Mutilla europcca and 2 species 
of Bapygaj one of them B.pedestris (Gerst.) . Of Anthophila 56 
species were detected, 37 of which are distributed nearly all over 
Europe. 
Jaennicke has published (Berl.ent. Zeitschr. 1867, pp. 141- 
155) a list of the Hymenoptera collected by him during the last 
three years in the neighbourhood of Frankfort on the Main. 
He enumerates 496 species, and describes three new Ichneumo- 
nidae. 
