1864.] 
473 
✓ 
and also in the sub-apterous G. forticornis n. sp., a peculiar arrange¬ 
ment for poisoning the tip of the ovipositor, which does not appear to 
have been noticed by authors.* Hitherto it has only been inferred ana¬ 
logically that Cynips 9 has an apparatus for poisoning its ovipositor, 
when it lays an egg in the bark or the bud. The following facts go to 
explain the physical means by which this very curious process is ac¬ 
complished. 
Take a recent or a relaxed specimen of some gall-making 9 Cyni- 
pide, e. g. G. q, aciculata 9 , and it will be noticed that almost invari¬ 
ably in repose, instead of the sheaths of the ovipositor being exserted, 
as they are in the Inquilines, nothing is seen resembling a sheath but 
a small, hairy, tuberculiform projection, which I shall call the “dorsal 
valve,at the top of the 7 th abdominal joint. (See Fig. II, 7.)f Now 
take a pin and push this “ dorsal valve ” backwards, and the sheaths 
will start out and assume the position shown in Fig. I. ss, disengaging 
from between them the tip of the ovipositor (Fig. I. o), which is curi¬ 
ously curved so as to lie conveniently between them when they are in 
their usual position (Fig. II. o.) A further examination and a dissec¬ 
tion of the parts will show that this “ dorsal valve” (Fig. II. 7) com¬ 
poses the upper part of a narrow vertical groove, visible only from be¬ 
hind, sufficiently deep to receive the whole breadth of both sheaths, 
and formed by the sides of the 8 th dorsal joint, which is united by a 
free suture with the 7 th, but with the exception of the “dorsal valve” 
can only be seen when viewed from behind. (Fig. V, 8 .) This groove I 
shall call the “ caudal groove.” Concealed in the abdomen, with its edge 
occasionally slightly projecting towards the “ ventral valve” (Fig. I. y ) 
there lies a singular, horny, circular, vertically compressed, black, pol¬ 
ished piece (Fig. VI.,) from which the sheaths (ss) behind and the 
ovipositor (o) in front take their origin, and which is strongly connected 
by a muscular attachment (m) to the upper part of the dorsal joints 6 
and 7. This piece is figured by Westwood (^hitrod. II, p.T21, fig. 19 ^), 
and is evidently from the organs attached to it the homologue of the ter- 
* I obsei’ve the same thing in six other species belonging to A. I. recently 
received from Baron Osten Sacken and Mr. Bassett.—March 14, 1864. 
f There ought to be a suture between the 7th dorsal and the dorsal valve,” 
but through a blunder of my own it is not shown either in Fig. I or Fig. 11 
though it appears in Fig. VI. 
