PREFACE 
This is a book for collectors of dragonflies and for students 
of their natural history. It aims to furnish a ready means of 
finding the names of our North American species, and to report 
some observations on their habits. It contains keys, and de- 
scriptions and figures. The keys are guides: the descriptions 
and figures are together diagnostic. Both adult and immature 
stages, so far as known, are included. 
Dragonflies are unique insects. They are very beautiful. 
They are wonderfully made. Their amazing shift from aquatic 
to aerial life at transformation is of absorbing interest. The 
completeness of their mastery of aerial navigation is a perpetual 
marvel. Surely these things are worthy of becoming a part of 
the common intelligence. We have sought to make them better 
known by providing the means for cultivating personal ac- 
quaintance with them. 
This ts a book for collectors: and we have tried to tell what 
the collector will want most to know, and there to stop. Data 
that belong to a treatise rather than to a guide we have omitted. 
There is elsewhere available (Tillyard’s ‘Biology of Dragon- 
flies’’) a treatise that deals with morphology, development and 
world fauna. Bibliography that is elsewhere available (Mutt- 
kowski’s ‘Catalog of the Odonata of North America’’) we have 
for the most part omitted to save space. After a brief intro- 
duction the two things included are: (1) enough description 
to serve for the recognition of the species, and (2) the best 
knowledge that is available concerning the habits of the spectes. 
Hence, conciseness and not completeness of description has 
been our object. Only the more salient diagnostic characters 
(usually color characters and venation) are stated. Our dragon- 
flies all have a prothoraz, though it ts rarely mentioned in the 
description of this book. The ultimate criteria for species are 
oftenest found in the accessory genitalia, and these we hope we 
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