Vol. xxiii] ENTOMOLOGICAL NEWS. 283 
R. F. Pearsall on Geometrids, p. 205. Two new species, and numer- 
ous new records; no collector given. 
E. M. Ehrhorn on Coccide, p. 275. Several new species; no com- 
parison with allies. 
A. D. Macgillivray on Empria, p. 305. 21 new species; no compari- 
son with allies. More species on p. 341 et seq. 
Barnes & McDunnough on Cea on p. 318. Two new species; no col- 
lectors given. One has two localities, type locality not stated. 
C. R. Crosby on Derostenus, p. 414. New species; no comparison 
with allies. 
T. W. Fyles on Gnorimoschema, p. 422. New species; no comparison 
with allies. 
T. D. A. CocKERELL,. 
Tur NortH AMERICAN DRAGONFLIES OF THE GENUS AESHNA, By E. M. 
Walker, B.A., M.B., Lecturer in Zoology in the University of 
Toronto. University of Toronto Studies, Biological Series, No. 
11, University of Toronto Library: Published by the Librarian, 
1912. Pp. viii, 213. 28 plates (6 of them in colors). Received 
April 20, 1912. Price, $2.00. 
This monograph, by the Editor of The Canadian Entomologist, deals 
with the species of Aeshna, in the narrower sense (excluding those re- 
ferred to Coryphaeschna Williamson), which have been found north of 
Mexico. It is doubtful whether anyone hitherto has produced a work 
treating of so many aspects of a group of Odonata as this one does. 
The systematic portion occupies pages 56-202. Preceding it is a discus- 
sion of the taxonomic characters of adult and of nymph; the variations 
of the adults, climatic, colorational and geographic; and the general life- 
history. 
The discussion of the taxonomic characters devotes much space to 
descriptions of the color-pattern and external genitalia of the adults 
and to the relationships of the Aeshninae of the world inter se, The 
author’s views on this latter subject are summarized in a phylogenetic 
tree (p. 24), according to which Gomphaeschna, Jagoria, Linaeschna, 
Boyeria, Allopetalia, Basiaeschna, Oplonaeschna and Aeshna are placed 
as the most generalized of living genera. Aeshna is thought “to suggest 
a polyphyletic origin from several parent genera resembling Basiaeschna 
and Oplonaeschna,” while Anax is considered to be in most respects 
“very highly specialized.’ 
The climatic variations noted are that “with an increase of the 
mean summer temperature there is an increase in the length and a de- 
crease in the depth of [abdominal] segment 3, and an increase in the 
length of the female appendages.” (p. 29.) 
