1864.] 
475 
On the other hand, in all the species belonging to A. II. which are 
known to me, the sheaths of the ovipositor project considerably beyond 
the dorsal valve” and often very considerably. Stjnerges rlioditifor- 
mis n. sp. forms an apparent exception, but on relaxing a specimen it 
is found that that species has the “ dorsal valve” unusually small, and 
that what seems the “ dorsal valve” is in reality the projecting tip of 
the sheaths. Not only is it the case that in all species belonging to 
A. II. the sheaths project beyond the “ dorsal valve,” but it is also 
very generally found here that the tip of the ovipositor in many indi¬ 
viduals of each species projects from between the tips of the sheaths. 
For instance, out of 28 9 rhoditiformis 19 individuals have the tip of 
the ovipositor thus projecting. On the contrary, out of nearly two hun¬ 
dred 9 specimens of various species belonging to A. I. now before me, 
the only two I can find with the ovipositor thus projecting are the very 
two which, as before stated, have the sheaths themselves projecting 
from the “dorsal valve,” viz. G. gciUee tmctorise. and the unique speci¬ 
men before referred to.* The reason is obvious. If the spoon-shaped tips 
of the sheaths are compressed in the “ caudal groove,” as in the group 
A. I. with the exception of the above mentioned two species, they 
allow no exit to the ovipositor, and at the same time prevent the gummy 
matter, which I suppose to be the gall-producing poison, from oozing 
out. If on the other hand, as in all the species known to me belong¬ 
ing to A. II., the spoon-shaped tips of the sheaths project beyond the 
“ dorsal valve,” the result will be that the ovipositor, as we find to be 
Out of 34 9 specimens sent me by Mr. Bassett of C. q. o'peraior 0. S., the 
anomalous Psenide above referred to, 20 have the ovipositor detached from the 
sheaths and reposing in the ‘^ventral valve”, and 14 have it projecting from 
the tip of the sheaths.—March 21, 1864. 
(^^@**The following note refers to p. 474 line 28, and was accidently omitted.) 
The hair-like recurved tip of the ovipositor, which makes its appearance in 
all the specimens, over 20 in number, which I have examined, is shown by a 
good lens to be composed of the two normal bristles thrust forwards from the 
tip of a more robust and apparently channelled seta, in which they travel 
backwards and forwards. Probably, after the tips of the two bristles have ab¬ 
sorbed the gall-producing poison, they are retracted into the robust seta, before 
the whole apparatus is thrust into the leaf, bud or bark, whence the future gall 
will arise. Thus the poison will be sure of being conveyed, undiminished in 
volume, to the appropriate spot. 
