NO. 2199. A NKW SPECIES OF D RAGONFLY-CURRIE. 225 



metrical, neiirly vertical inferior tooth at about three-fourths dis- 

 tance irom base to apex; in ventral aspect of the appendage (pi. 28, 

 ficr 2) this tooth is located at the posterior end of an ovate con- 

 cavity. Inferior appendage (pi. 28, figs. 1, 2, and 3) laterally and 

 apically black, hairy, about the same length or a little shorter than 

 the superiors, not extending so far laterad, its hind margin moder- 

 ately excavate. 



Accessory genitalia of second segment (pi. 28, fig. 7) : Anterior 

 hamules pale yellow at base, dark apically and behind; posterior 

 hamules nearly vertical (directed a little posteriorly), large, pale 

 yellow, ending in a hook, brown at tip, which is directed forward 

 and, viewed ventrally, inward; vesicle large, erect, dark brown, lat- 

 erally shiny. 



Type-locality.— Lnkelnnd, Prince Georges County, Maryland. 



T7/pe.— Cat No. 203G7, U.S.N.M. 



Described from one specimen collected by the author May 22, 1915, 

 while it was resting in a field along the Anacostia Eiver. 



Before the drawings and photograph were made and the descrip- 

 tion drawn up, the specimen of Gomphus parvidens met Avith an 

 accident, in which the left superior appendage was lost and the 

 wings were slightly damaged. AVhen collected the specimen was not 

 fully chitinized, and in consequence segment 10 is somewhat distorted 

 ventrally; but it was bristled, pinned, and spread the day after col- 

 lection and there was little if any fading or discoloration of the 

 bright markings in drying. 



Gomphus parvidens (pi. 28, figs. 1, 2, 3 and 7; pi. 27, figs. 1 and 2) 

 may be distinguished from G. hrevis Hagen (pi. 28, figs. 6 and 10; pi. 

 27, fig. 3), G. ahhreviatus Hagen (pi. 28, figs. 4 and 8), and G. viridi- 

 frons mne (pi. 28, figs. 5 and 9), to which it seems most nearly re- 

 lated, by the narrower pale stripes of the thoracic dorsum (compare 

 pi. 27, figs. 2 and 3), the more symmetrical shape of the male supe- 

 rior appendages, viewed laterally, and the shape of the accessory 

 genitalia of the second segment. 



"^ The following key will help in distinguishing the males of these 

 four species: 



Key for the separation of the males of Gomphus parvidens, G. brevis, G. viridi- 

 frons, and G. ahhreviatus. 



1. Dorsal thoracic pale stripe (pi. 27, fig. 3) anteriorly from one-half as wide 

 to wider than adjoining middorsal dark area ; apical half of superior ap- 

 pendage viewed from side bilaterally unsyminetrical 2 



Dorsal thoracic pale stripe (pi. 27. fig. 2) anteriorly about one-fourth as 

 wide as adjoining middorsal dark area ; apical half of superior appendage 

 viewed from side almost bilaterally symmetrical parvidens. 



77403 — Proc. N. M. vol. 53 — 17 15 



