806 General Notes. : [ November, 
CETONIA INDA.—This common insect which in former years 
was a harmless beetle feeding in early spring on the sap of freshly 
cut maple trees has, within two or three years, become very abun- 
dant and destructive in different parts of New England. During 
the past summer it collected in great numbers on green corn, 
-eating the kernals and partly destroyed a field in Middleboro, 
Mass., as we learn from Prof. Jenks.—A. S. P. 
CAUSE OF THE TWISTING OF SPIRAL SHELLS.—At the end of his 
essay on the development of the pulmonate Gasteropods, M. Fol 
inquires into the cause of asymmetry of univalve shells ; by most 
authors it has been ascribed to the folding round of the shell; 
ering, however, regards the torsion of the shell as due to the 
asymmetry of the viscera. Fol regards both these opinions as 
too extreme, as in the Heteropoda asymmetrical arrangements 
manifest themselves at an extremely early period. In Helix and 
Limax the torsion does not appear so early, and is seen simulta- 
neously in the viscera and in the shell. To explain the phenom- 
ena, it seems to be necessary to note the process of segmentation 
of the ovum; but here unfortunately there is but little informa- 
tion. The fact that organs like the kidneys, which are, as we 
the commencement of the embryonic period. In conclusion, as 
reported in the Journal of the Royal Microscopical Society, the 
author points out how recent observations tend to favor the rees- 
tablishment of the Vermes of Linnzus. It is impossible, Fol 
says, to compare the molluscan larva with a segmented worm 
larva; they only correspond to the cephalic portion of the larva 
mented animals which have fused their segments, but they are 
animals which have remained simple. In the Vermes, on the 
other hand, the larval form (Lovenian, veliger, trochosphere) can, 
_ with variations in form, be traced through “worms,” Annelids, 
Bryozoa, Brachiopods, and even Echinoderms, and these all form 
a phylum quite distinct from that of the Arthropoda on the one 
se and of the Chordata (Tunicata and Vertebrata) on the 
other. 
_ Tue Young OF THE CRUSTACEAN LeuciFER, A NaurLIus.—One 
of the most interesting observations which we have made this 
summer is, that Leucifer leaves the egg as a Nauplius. As Fritz 
Nauplius from the egg, so the occurrence of a Nauplius is proved, 
_ absolutely, in one stalk-eyed Crustacean. 
As almost nothing was known about the habits of Leucifer, and 
nothing whatever about its embryology, I have devoted especial 
