EXPLANATORY NOTES 47 
Citations of species—Under each species we cite: 
(1) The original description. 
(2) The page in Muttkowski’s Catalogue of the Odonata of North 
America* (Milwaukee, 1910) whereon other citations may be found. 
(3) Descriptions and additions to knowledge made since the publi- 
cation of that Catalogue. 
(4) Omissions from that Catalogue, and amendments. 
All these citations are by the numbers corresponding to the years 
of publication as indicated in the list of papers beginning on page 359. 
Genera and species have been numbered, and all these numerals 
have been assembled on a single page at the end, to serve the collector 
as a concise checking and exchange list (p. 366). 
For the convenience of the user, size and distribution are condensed 
to a single line at the head of each description, and both are stated 
broadly. Color is used for easy marks of guidance, venation for positive 
recognition of the groups, and figures of genitalia are given where 
needed, for criteria of species. Only experience will enable one to judge 
how much latitude must be allowed for variability in all these, especially 
in color and size. Colors fade with age, greens becoming yellow, and 
blues discoloring to black; they also vary in extent according to the 
age and condition of the specimen, and descriptions must be interpreted 
with some judgment and some discernment as to the trend of patterns. 
Binomials only—A name is merely a name and not a treatise on 
relationships: hence our decision that, if a group of individuals is 
distinct enough to bear a name, that name shall be a binomial. 
ABBREVIATIONS 
Beauv., Beauvais McL., MacLachlan 
Brim., C. 8S. Brimley Mrin., R. Martin 
Britn., Elsie Broughton Mtk., R. A. Muttkowski 
Burm., H. Burmeister Ndm., J. G. Needham 
Calv., P. P. Calvert Prov., Provancher 
Charp., Charpentier Ramb., P. Rambur 
Ckil., T. D. A. Cockerell Scud., S. H. Scudder 
Dav., W. T. Davis Selys, Baron de Selys 
Fabr., J. C. Fabricius Smn., Marian Seeman 
Garm., P. Garman Walk., E. M. Walker 
Hag., H. A. Hagen Whed., A. D. Whedon 
Arvy., F. L. Harvey Whts., F. C. Whitehouse 
Holl., Holland Wils., C. B. Wilson 
Kict., D. 8. Kellicott Wmsn., E. B. Williamson 
Kndy., C. H. Kennedy Wstwd., Westwood 
* For sale by Milwaukee Public Museum: price $1.25 postpaid. 
