NO. 2107. DRA00NFLIE8, WASHINGTON AND OREGON— KENNEDY. 271 



in couple, but I saw none copulating or ovipositing. A month 

 later the species had reached its greatest abundance. The creek 

 then was low; not more than 15 second-feet of water was flowing. 

 Argias were abundant on the gravel bare and exposed gravel-strewn 

 riffles, and among the pink willow roots oviposition was in progress. 

 On August 8 the Argia, was yet the most abundant species, but by 

 August 24 the number was less than one-fourth its pre\dous maxi- 

 mum. On September 7 only two Argias were seen, and on September 

 14 none were found. Its season had ended as the autumnal species 

 were reaching their height, ArcUlestes californica, Lestes congener, 

 Ischnura perparva, AesTina palTimta, Aeshna umbrosa occidentalis, and 

 Sympetrum vicinum being the only species on the Aving. Some 

 individuals emerged as late as August 7, though none were noticed 

 on later dates. 



The following is a description of this Argia, which was found to 

 be undescribed and which I have named for my mother, who has 

 ever encouraged my interest in entomology. 



ARGIA EMMA, new species. 

 Figs. 27-30, 35-36, 39-41, 48, 50-51, 54-61, 65-70. 

 This is a large species of Argia, but is not as robust as Argia vivida. 

 It IS a species not brilliantly marked, and is comparatively free from 

 pile. 



Length of abdomen: Male, 27-31 mm.; average, 29.1; female, 

 27-32; average, 29.35. Length of hind wings: Male, 21-24; aver- 

 age, 22.75; female, 22-25; average, 23.2. 



Type.-C^t. No. 19038, U. S. N. M. A male, from Satus Creek, 

 Yakima County, Washingtoji, August 7, 1913. 



AUotype.-Q^t. No. 19038, U. S. N. M. A female from Satus 

 Creek, Yakima County, Washington, August 7, 1913. 



ifaZe.— Thorax robust, abdomen slender. Legs long, the last 

 femora reaching to the second abdominal segment. Wings noticeably 

 narrower than in the female, and in the fully colored specimens with 

 a faint bluish or steely sheen. Stigma surmounting only one cell 

 which is usuaUy larger than the stigma. Among 20 males tabulated,' 

 the usual number of antenodal cells was 4 in each fore wing and 3 in 

 each hind wing. Variations of one or two occurred either way. 

 The average for the fore wings in the 20 examples was 3.9 and for 

 the hind wings 3.3. The male illustrated in figure 27 was not included 

 m the 20 tabulated. In the accessory genitaha are pecuharities 

 which are probably specific. (See figs. 50 and 51.) The ventral 

 hmh of the anterior hamuh, i. e., the horizontal ventral edge, is hicrh 

 and tlnn compared with the same in vivida, where it widens cephalad. 

 The postenor hamuh are rounder, when viewed ventrally, than in 

 vivida. The most marked pecuHarities occur in the penis, which 



