MEMOIES OF THE FATIOiTAL ACADEMY OF SCIENCES. 
279 
RECAPITULATION OF THE MORE STRIKING FEATURES IN THE ONTOGENY OF CERURA. 
Congenital cliaracters. 
(1) The larv«a hatches with tuhy developed stenuipoda, iudicatiug that the genus has 
-descended with little modification from a form like Macnirocampa. 
(2) The prothoracic horns are longer, better developed than in the mature worm, showing 
that in this respect also the genus has originated from the Heteroc.ampinm. 
Acquired characters. 
(3) The head is smaller in proportion to the body than usual, owing to the great width of the 
prothoracic segment. 
(4) The body is all brown above in the first stage, beginning to turn green in the second, and 
in the third becoming nearly as in the last stage. Thus the colors are more diversified, with more 
green in the fourth and fifth stages, rendering the now more exposed larva more adapted for 
protec^tion by the resemblance of its markings to the yellow and red sxiots on the green leaves of 
its food plant, which appear early in autumn. 
{“)) The dorsal hum}) on the third thoracic segment does not seem to apiiear until the last 
stage. (Dr. Dyar, however, tells me that it aiipears in G. multiscripta in stage III.) 
(6) The filamental legs retain their shaxie from the first to the last stage, but if anything are 
-a little shorter in the last. On the other hand, the spinules in the third stage become larger on 
the underside than before, the filaments being held curved up more than before, so that the 
defensive spines on the underside, in response to external stimuli, have developed more ra])id]y 
than those on the upi)er side. 
(7) Novel structures are the very long and ivell-developed supraaiial plate and the pair of 
‘Coproliferous spines (or dungforks) arising from the paranal lobes, and available for tossing away 
the pellets of excrement. These seem to be peculiar to the genus in this family. 
