Botany and Zoology. 73 
Corda. Since then many authors, especially Germar and Golden- 
berg, have added to our knowledge, until now perhaps one hun- 
dred species are known. Yet insect remains in the older strata 
may still be looked upon as the greatest rarities, and by far 
larger part of them are known to us only by their wings. 
t is of course of prime importance that we should understand 
the relative subordination of the larger groups in insects before 
investigating their order of succession in time; for one of the 
and geological relations has been in the erroneous views which 
_ have been maintained of the relative rank of the suborders of 
Hexapods and of their division into series. The author con- 
ing the Hymenoptera, Lepidoptera and Diptera; the latter the 
_ bination of characteristics in Eugereon and other early insects and 
_ toaccept, but with somewhat different limits, the term Palzodicty- 
_ optera applied to this group by Goldenberg. He discussed the 
_ times of appearance and relative abundance of the different subor- 
_ ders of Hexapods and concluded with the following recapitulation: 
xapods known 
om 
Arachnids and Myriapods—appeared simultaneously in Carbonif- 
erous strata, (2.) All Carboniferous and Devonian insects are 
the Heterometabola; of Orthoptera and Neuroptera ; or of Neu- 
tera proper and Pseudoneuroptera. (4.) The ise is ects 
Ww e 
rop 8 
either belong to comprehensive types related to the ower 
ous. (11.) The serics of facts presented to us by the progress of 
geological research leads to the conviction of the probable exist- 
ence and possible discovery, in the Devonian and even m the 
4 ation, ‘ed insects, still more generalized in 
_ Structure than any yet detected in the Paleozoic roc 
