Vol. xxvii] ENTOMOLOGICAL NEWS. 207 
The Lines of Descent of the Lower Pterygotan Insects, 
with Notes on the Relationships of the other Forms. 
By G. C. CramptTon.* 
(Continued from page 258) 
The interrelations of the different groups making up the 
section Neuropteradelphia are extremely complicated, and can 
be worked out in detail only after studying more of the primi- 
tive and annectent forms than are at present accessible. Enough 
material is available, however, to indicate the following rela- 
tionships. 
The Raphidoides (Aponeuroptera). or Raphidian group is 
closely related to the Sialid group, but has tended to branch 
off along its own line of development. The Sialoides (Mega- 
neuroptera) or Sialid group comprises such insects as Sialis, 
Corydalis, Chauliodes, etc., and is one of the most primitive 
of the Neuropteroid section, forming one of the main trunks 
upon which the other lines of descent converge. This group 
contains some of the largest of the Neuropteroid forms (hence 
the name Meganeuroptera). 
The Chrysopoides (true Neuroptera) or Chrysopid group 
comprises such forms as the Chrysopidae, Hemerobiidae, Co- 
niopterygidae, etc., and is rather closely related to the Sialid 
group, the two together constituting the most primitive lines 
of Neuropteroid insects. 
The Myrmeleonoides (Zygoneuroptera) or Myrmeleonid 
group is related to both the Sialid and Chrysopid groups and 
has retained certain characters suggestive of a relationship to 
the Zygoptera, or Libellulid forms. This group contains such 
insects as the Myrmeleonidae, Ascalaphidae, Nymphes, etc., 
all of which are quite primitive forms, so that it is rather diffi- 
cult to determine which of the three groups (Sialids, Chryso- 
pids or Myrmeleonids) is the most primitive, although the 
Sialids are apparently as little modified as any. 
The Mantispoides (Dictyneuroptera) or Mantispid group is 
related to the Chrysopid group, and also shows some affinities 
_ * Contribution from the Entomological Laboratory of the Massa- 
chusetts Agricultural College, Amherst, Mass. 
