Observations upon Luminous Animals. 105 
in which it terminates are seen covered with small cups or 
suckers. 
Fig. 7. The beroe fulgens, discovered by me, shown in 
its. most elongated or relaxed form, which it assumes com- 
monly when swimming quickly. 
Fig. 8. The same animal in the most contracted form. 
Fig. g. The minute species of medusa, discovered by me, 
which i is the most frequent cause of the luminous appear- 
ance of the sea, represented of the natural size. 
Fig. 10. The same animal maguified, exhibiting a puck- 
ered or tucked-in appearance on one side. 
Fig. 11. Is the animaleule discovered by Forster, of the 
natural size. 
Fig. 12. The same, greatly magnified, to show the in- 
testinal, parts, Both these figures : are copied from the ori- 
ginal drawings, in the. possession of the Right Hon. Sir 
Joseph Banks. 
Fig. 13. Is an enlarged view of the inferior surface of 
the abdomen of the lampyris lucida, after the integument 
had been removed. aaa represent the three masses of lu- 
minous substance which are applied to the three last rings 
of the abdomen. 00 the arrangement of cellular or inter- 
stitial substance on the other abdominal rings, which gives 
the pale colour to the whole belly of this insect. 
Fig. 14. Represents the common glow-worm, with the 
posterior portion of the back cut’ aw ay to expose the sacs 
of luminous matter in situ on the last ring of the belly. @ 
indicates the sac of one side; the intestine is seen to lie 
between them. 
Fig. 15 and 16. Are the sacs of the glow-worm prodi+ 
giously magnified to show their structure. Fig. 16 is cut 
open to expose the luminous matter it contains : the coat 
of the sac is still seen to preserve its figure. 
Fiz. 17. Is the elater noctilucus, with the shell of the 
corcelet removed on one side, by which the organ of light is 
uncovered. a@ the yellow transparent spot of the corcelet. 5 
the oval mass of luminous substance surrounded by an irras 
diation of the interstitial substance. c the ends of the mus- 
cles which were on the inside of the coreelet. i 
Fig. 18. Is the posterior angle of the corcelet of the elater 
nectilucus magnitied. a@ the radiated appearance which the 
interstitial substance has round the oval mass of luminous 
matter. This mass is seen to consist of a number of smaller 
parts. / shows the appearance of the interstitiat substance, 
where it passes down between the muscles. ¢ the ends of 
the muscles of the back, d the shell of the corcelet. 
Fig. 
