392 DR. J. B. HICKS ON THE ORGANS 
Sirex gigas possesses two forms of these organs, as is shown at P. They are found 
freely scattered over the segments on one side, the other being free from them. The 
consist of— | l 
lst. A number of depressions, diameter 315 inch, in the centre of which is a closing-in 
membrane; beneath is a tube passing through the antenna-wall, and leading to å mem- 
brane-sac, as is shown at fig. 14, fig. 2, fig. 35. | 
2nd. A number of closing-in membranes, having a distinct cavity behind them, in the 
antenna-wall. They are shown in section at fig. 4, and from above at fig. 3 a. Diameter 
at surface 3965 inch. These appear to be nearly the same as at O. fig. 2, and similar to 
those in Carabus. | 
We come now to the Lepidoptera. In the Diurna I have examined 
Gonepteryx rhamni, 
Pieris, or Pontia brassice, 
Pontia rape, 
Vanessa urtice, 
Hipparchia Janeira, 
Lycæna Phleas ; E 
and I find the same description will apply to them as to the antenna of Argynnis Paphia 
(of which I have given a description and figure in the paper before referred to), with the 
exception of a variation in the comparative number of organs, and of the number of 
cavities. 
In the Moths I have as yet only found the smaller organs described in Argynmis 
Paphia : their position on the pectinated forms in the Bombicide and Geometride seems 
to be universally towards the apex of the division; and in the forms less deeply pecti- 
nated they are found on those sides where the deepest indentation exists. They are more 
numerous towards the apex of the antenne. 
lg Oi ti 
E g. 2. At fig. 3 the same is magnified, showing 
in the dotted lines the existence of a cavity in the interior. | 
Q. shows them on the dilated end of the combs in Odonestes potatoria (Drinker 
Moth) : fig. 5 shows one enlarged. | 
This condition I have found to exist in | 
På 
| d of each segment, as in the Buff Tip (Pygæra buce- 
phala), and Yellow Underwing Moth (Tryphæna Bomba). The latter I have figured at 
