INTERNAL ANATOMY OF INSECTS. 39 
of Copris the corrugations form a perplexed labyrinth ; 
in the caterpillar of the puss-moth the plaits are so nar- 
row as to look like rays a ; and in some Dynastidce the 
lips approach to a lamellated structure. Again, in Hy- 
drophilus caraboid.es the upper lip, and in Dytiscus cir- 
cimiflexus, both lips seem formed of elegant plumes b : a 
similar ornament distinguishes the inner edge of the lips 
in the caterpillar of the great goat-moth (Cossus lig- 
niperda) and others c . In the grub of the rhinoceros- 
beetle (Oryctes nasicomis) the margin of the lower or in- 
ner lip is decorated by pinnated rays, which enter the 
cellular membrane that covers the upper lip d : in this 
larva, and that likewise of the cockchafer, the two lips 
are formed of different substances; in the last the upper 
or outer one consists of a perforated cellular membrane, 
through which the air can pass, while the lower or inner 
one is a cartilaginous valve that closes the orifice e : in 
the former this valve is surmounted by a boss f . In the 
pupa of Smerinthus Populi, a hawk-moth not uncommon, 
and of some dragon-flies (Libellulajlepressa), the margin 
of the two lips is crenated, probably with notches which 
alternate, that the mouth of the spiracle may shut more 
accurately s . The substance is unusually thick in the spi- 
nose caterpillars of butterflies ; and in the pupa of one, 
Uria Proteus, it is villose. 
Under the present head I may observe, that in some 
cases, as in the puss-moth, and the larva of the common 
a Sprengel, 7- 1. in./. 30. » Ibid, t. ii.f. 22. t. iii./. 29. 
c Plate XXIX. Fig. 29. 
J Ibid. Fig. 1G. Sprengel, Ibid, 9. t.l.f. 4—6. 
' Ibid. 9. t. If. 9. f Plate XXIX. Fig. 1C. a, 
' Sprengel, Ibid, t.iu.f. 37. 
