392 DR. J. B. HICKS ON THE ORGANS 



Si)-e:c 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 heing free from them. They 

 consist of — 



1st. A nixmber of depressions, diameter g^g inch, in the centre of which is a closing-in 

 membrane ; beneath is a tube passing tlirough the antenna- wall, and leading to a mem- 

 brane-sac, as is sho'mi at fig. 1 b, fig. 2, fig. 3 b. 



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 3^00 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, 

 Fieris, or Pontia brassicce, 

 Fontia rapm, 

 Vanessa urticcB, 

 Hipparchia Janeira, 

 I/ycosna Fhleas ; 

 and I find the same description will apply to them as to the antenna of Argynnis Faphia 

 (of which I have given a description and figure in the paper before referred to), with the 

 exception of a variation in the comparative nimiber of organs, and of the number of 

 caWties. 



In the Moths I have as yet only found the smaller organs described in Argynnis 

 Faphia : their position on the pectinated forms in the JBombicidce and Geometridee 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 

 nimierous towards the apex of the antennae. 



I have figured those of Arctia Caja (Great Tiger Moth) at Q., showing their position in 

 the male at fig. 1, and in the female at fig. 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 



Drinker Moth {Odonestes p)otatoria), 

 Yellow- tailed Moth {Forthesia chrysorrhoea), 

 Vapourer {Orgyria antiqua). 

 Lackey {Clissocampa neustra), 

 Ermine (Filosoma lubricipeda), 

 Willow Beauty {Aids rhomboidaria). 

 In those antennae which are simple and filiform, I find that they exist on one side only, 

 and situated towards the distal end of each segment, as in the Buff Tip {Fygcera buce- 

 pJmla), and Yellow Underwing Moth {Tryphcena Bomba). The latter I have figured at 

 R. : fig. 1 shows their position ; fig. 3 shows a magnified view of them, with the peculiar 

 markings on the cuticle, while at fig. 2 the nerve (a) is shown distributing branches to 



