( ska”) 
North-American Smerinthine genus Ceratonia, in which the 
larva possesses four thoracic spines in addition to the caudal 
horn. The comparison leaves no doubt that the Sphingide are 
a specialized offshoot from the not very remote ancestors of 
the Saturnian Bombyces, and that they are connected with this 
- group through Aglia, on the side of the Bombyces, and the 
Smerinthine genera on the side of the Sphingide. 
3. The cause and meaning of the Sphina-like attitude.—This 
attitude, which is equally marked in Aglia, is due to the 
strain caused by gravity upon the anterior unsupported part 
of the body, together with the compensating muscular 
reaction. It is most marked in the vertical position of the 
larva with the head upwards, and also in the horizontal 
position with the back downwards, and least of all the 
position of the Sphinx,—horizontal with the back upwards. 
4. A graphic method of representing the growth of larve.— 
Attention was called to the fact that many important points 
in the ontogeny could be seen by a glance at a properly-con- 
structed ‘‘curve’’ of larval growth, in all stages. 
5. The means of defence of the larva of Stauropus fagi.—The 
larva, when undisturbed, is extremely well protected by re- 
sembling a withered beech-leaf; disturbed, it assumes an 
alarming attitude, in which it resembles a highly-idealised 
spider ; further alarmed, it exposes two black marks on each 
side, which probably suggest ichneumon stings and thus 
warn off an insect enemy. 
6. Meaning of the black colour of the eggs of Paniscus 
cephalotes. — These external eggs are of a shining black 
appearance, and highly conspicuous against the skin of many 
larve ; they doubtless serve to warn off other ichneumons 
which lay similar eggs, and also those which lay internal 
eggs, for the black eggs resemble the scars (which always 
become black) made by the latter ichneumons in the act of 
oviposition. 
7. Defensive meaning of ‘* tussocks”’ and associated black inter- 
segmental markings. — The ‘‘ tussocks” are defensive struc- 
tures; they are held very conspicuously when the larva is 
alarmed, and look like solid outgrowths, which would be 
PROC. ENT. SOC. LOND., Iv., 1888. G 
