NORTH AMIORICAN ODONA'I'A. 227 



No erect pyninii(lnl horn on the front of the head. 



A tubercle ou either side of the top of the head ; 10 very short, a dorsal 

 hook on 3-9, a sharp lateral spine on 8-9, those of 9 exceeding the 



appendages 24. Epicordiilia. 



No such tubercles. 



Lateral spines of 8 very short, of 9 long, sharp, divergent, much lon- 

 ger than theappendages..25. Tetragoneiiria (group of cyxosMm). 

 Lateral spines of 8-9 flat, sharp, incurved : of 9 not longer than the 



appendages 27. Soilialoclilora (group of lihera). 



Subfamily Libellnlinie : 



Middle (dorsal) terminal appendage a little longer than the inferiors 

 (ventrals), all spinous. Teeth on opposed margin of lateral labial 

 lobes flat, not interlocking, 8 and 9 with a long, sharp, incurved 



lateral spine 28. Paiitala. 



Middle (dorsal) terminal appendage shorter than the inferiors, laterals 

 without spines^. Teeth on opposed margin of labial lobes much 

 shorter than in Pantala, interlocking in a nearly straight line; 

 otherwise as in PawtaZa 29. Traiiiea. 



The nymphs of but a small proportion of the species are known, 

 so that no attempt is made in this paper to define their specific char- 

 acters. 



List and Characters of the Species. 



[N. B. — The following explanations, in addition to those contained in the 

 preface, are required for the proper understanding of the subsequent test. Much 

 greater importance is attached to structural than to color differences; what are 

 regarded as the important specific characters are indicated by italics. Although 

 teneral colors (see p. 203) are often mentioned, the colors usually described are 

 those of the adult insect, and allowance must be made for such age-differences 

 in identifying specimens. The wings are to be understood as being colorless, 

 unless otherwise stated. The abdominal segments are denoted by the numerals 

 1 to 10. Measurements are always expressed in millimetres, and the length of 

 the abdomen always includes the terminal appendages. Names of collectors 

 have usually been cited at the end of the list of localities for each species in such 

 cases where their labors have extended the known areas of distribution beyond 

 those already published by Hagen (37), de Selys, Banks (38) and others. Ab- 

 breviations employed are Sup. app., superior appendages. Inf. app. inferior ap- 

 pendages. Abd., abdomen. H. w.. hind wing. Phila., Philadelphia. Del. Co., 

 Pa., Delaware (bounty, Pennsylvania. N. J., New Jersey. Tvvp., Township. 

 A. E. S., W. I., C, collections of the American Entomological Society, Wagner 

 Free Institute of Science and of P. P. Calvert, respectively.] 



Subfamily 1. CALOPTERYGIN^. 

 1. Calopteryx Leach. 

 (Calepteryx) Leach, Edinb. Encyc. ix. p. 137, 1815. Amer. Edit, viii, pt. ii. p. 

 726, 1816. Selys, Mon. Calopt. p. 22, 1854. 

 1. i'alopteryx maciilata Beauv. 

 Agrion m. Beauvois, Ins. Afr. Amer. p. 85, Neur. pi. 7, fig. 3, 1805. C. m. Hagen, 

 Psyche v. p. 249. 1889. 



TKANS. AM. ENT. SOC. XX. SEPTEMBER, 1893. 



