IN THE ANTENNÆ OF INSECTS. 153 
. EXPLANATION OF THE PLATES. 
(All the figures are magnified.) 
TAR. XXIX. 
Fig. 1. Antenna of the Blowfly, Musca vomitoria :—a, antenna, showing both the smaller organs and the 
chambers; à 1, the smaller organs, having a diameter of zopp of an inch; 5 2, the apertures to 
the chambers, having a diameter of 355 to 1757 of an inch; c, aperture of chambers; c’, ditto 
as seen focused lower down; d, section of wall of antenna, showing 1, the smaller organs, and 
2, the chambers and their sacculi, the diameter of the largest being +45 of an inch. 
Fig. 2. Antenna of Helophilus pendulus :—a, antenna; 6 1, the smaller organs, having a diameter of 7757 
of an inch; c 1, do. do.; c 2, apertures to chambers, diameter +55 of an inch; c 28, do. do. 
focused lower down; c 2b, focused still lower; d, section showing the smaller organs at 1, 
and the chambers with their sacculi at 2. 
Fig. 3. Antenna of Tabanus bovinus :—a, antenna, with the third to the eighth joints furnished with the 
organs; à, enlarged view of the organs of various sizes. 
Fig. 4. a, Antenna of Tipula oleracea; b, antenna of Ctenophora ——?; c, antenna of Ctenophora bima- 
culata; d, section of organs; d, organs as seen from above, diameter ziyy of an inch. 
Fig. 5. Antenna of Argynnis paphia :—a, antenna showing the position of the organs; 41, small closed 
perforations of various sizes, the smallest 4,5, the largest 5753 of an inch; 5 2, openings to 
cavities, from 3357 to 1357 of an inch; c, last joint of the antenna, showing the openings to the 
cavities ; d, section of chambered cavities, with a projection or papilla in the centre of each, 
Tas. XXX. 
Fig. 6. a, Part of antenna of Apis mellifica; a 1, groups of organs; a 2, nerve giving off branches; b, 
view of organs, more highly magnified. 
Fig. 7. a, One joint of antenna of Eucera longicornis; b, saucer-shaped depressions, diameter from edge to 
edge 1757 of an inch; c, section of wall of antenna, showing sacs or cells beneath; c1, membrane 
closing in the openings in internal membrane, diameter 775; of an inch. 
Fig. 8. a, One joint of antenna of Andrena fulva; b 1, saucer-like depressions, with membrane in centre 
closing in the perforations; à 2, hairs; 1 and 2 are both surrounded by a ring of very minute 
tubercles ; c, section of wall of antenna. 
Fig 9. a, One joint of antenna of a species of Ichneumon; b, section of wall of antenna, showing the 
transparent membrane overarching and extending beyond the perforation of the internal wall; 
c, enlarged view of organs; membrane as seen from above, very penus, stretching. over 
like an inverted canoe; the opening beneath is the perforation of m internal membrane. 
Fig. 10. a, Antenna of Libellula depressa, showing the 3rd to the 5th joints with organs placed on one 
side of the nerve; 2, portion of wall of the 3rd joint; å 1, large sacs with plicated walls, closed 
externally by a delicate membrane ; 5 2, small simple sacs, also closed by membrane ; b 3, nerve 
proceeding to sacs; c, sacs of 5th joint. : 
- VOL. XXII. ^ 
