HYMENOPTERA. — PROCTOTRUPIDE. 169 
men, and formed, according to Latreille, of two valves composing a 
tube, and inclosing the true needle-like ovipositor: in the former the 
ovipositor appears at first sight simple, but is most probably formed of 
two valves closely united together, two sutures being perceivable. In 
the Gonatopides, Bethyllus, &c., the ovipositor is affirmed by Esenbeck 
to be converted into a true sting. My figures 78. 6. and 7. represent 
the composition of the ovipositor in Proctotrupes brevipennis. In 
78. 6. the two demi-sheaths are partially extended, showing the ovi- 
positor, which is defended by them when shut together. In 78. 7. the 
various parts are entirely separated, b and 6 representing the 
demi-sheaths, c the ovipositor itself channelled on the under side, and 
ce the two spicule playing in this channel, and which it will be seen 
are thus the representatives of the parts delineated with the same 
letters in the figures illustrating the Uroceride, Cynipide, and Ich- 
neumonidee. 
Many of these insects are exceedingly active, running and flying 
with great agility ; but few are capable of leaping. They are of very 
minute size, some being so minute as to be visible only to the naked 
eye when creeping up the glass of windows opposed to the light 
(Ichneumon [Mymar] atomos Zinn. ; Ichn. punctum Shaw, Trans. 
Linn. Soc. vol. iv. pl. 18. f. 1. Mymar Monas, Termo, &c.). Their 
colours are ordinarily black, varied with pitchy or brown. They may 
be taken in great numbers upon grass and other vegetables in the 
sweeping-net. Some frequent hot sandy situations, as Gonatopus *, 
Epyris +, &c., whilst others are found upon aquatic plants (as Thoron 
solidus /s., metallicus Hal.). I have observed that some species 
have a curious habit of alternately raising and depressing the abdomen 
when standing still upon hot sand-banks. They are parasites, but 
the transformations of very few species have been observed. La- 
treille, indeed, supposed that, as many of them are found on the ground 
and upon low herbs, their larve reside in the earth. It is, however, 
more probable that they deposit their eggs in other insects residing in 
such situations. 
* I have occasionally taken Gonatopus in damp situations, but generally in exposed 
hot sandy localities. Mr. Haliday generally finds it on the sand hills of the coast, 
and Mr. Paget in similar situations near Yarmouth. (See his Nat. Hist. Varmouth, 
Appendix. ) . 
+ I have repeatedly taken Epyris niger flying over hot sand-banks, both at 
Coombe Wood and near Bingen on the Rhine, just in the same manner as fossorial 
Hymenoptera, 
