6 
covered the Gomphide and Cordulegasteride, his second (’81) 
the Aschnidw, and his third (’90) the Synthemiine and Cor- 
duliime and also Tramea and Pantala. Hagen (’85) gave a greatly 
extended revision of the two families previously treated by 
Cabot (72). The large and abundant family Libellulide was 
not treated by them. Karsch(’93) gives descriptions, figures,and 
keys to West African nymphs. The characters assigned to the 
major groups in his keys are, as Dr. Calvert has pointed out, 
only locally or partially true. Lucas (97, 97a) has described 
and figured a few English nymphs, and Roster (’86,’88), a num- 
ber of Italian Zygoptera. Beutenmiller (’90c) has, given a 
bibliography of nymphal descriptions, excepting those in Cabot’s 
90. Needham (’97a,’99) gives suggestions on collecting and 
rearing nymphs. 
Among the general works, Dr. P. P. Calvert’s admirable 
paper (’93) deserves first mention. It includes a complete and 
accurate summary of all the more important biological and 
anatomical details concerning dragon-flies and their nymphs, 
with generic keys for both. Descriptions are given of the 
species of the region about Philadelphia, among which are 
most of our commoner forms. The phylogeny of the dragon- 
flies in general, with especial.reference to the structure of the 
gizzard, is discussed in a scholarly article by Dr. F. Ris (797). 
The principal monograph of American species is in Hagen’s 
well known “Neuroptera of North America” (’61). A num- 
ber of monographic papers have been published by Dr. Selys- 
Longschamps in Belgium. The best catalogue of species is 
that of Kirby (’90). It contains several surprising changes in 
nomenclature, one of which—the use of shna in place of 
Gomphus—is fortunately not well founded. Banks (’92) has 
listed the American species, and given a key to the genera. 
From an economic point of view, especially as to their utility 
as destroyers of obnoxious Diptera, dragon-flies are treated in 
Lamborn’s collection of prize essays (790). 
The numerous published lists of Odonata in this country 
contain much valuable information as to the life history of our 
