113 

 Smith and Pritchard: Odonato 



NYMPHS 



E. AGRIONIDAE COENAGRfONI DA E 



Fig. 4:14. Zygopterous naiads. a,c,f, Coenagrionidae; b, 

 Lestidae; d, e, Agrionidae (Wright and Peterson, 1944). 



Genus Tanypteryx Kennedy, 1917 



Adults of Tanypteryx have been taken in alpine 

 meadows, from California to British Columbia, but 

 | very few specimens are known. The only naiads 

 referable to this genus in North America were col- 

 lected by Vincent Roth in a mountain bog in Oregon. 

 His field notes state that he collected two naiads 

 j "on a moss covered bank at Parker Creek, about 

 3000 feet on Marys Peak, Benton County, Oregon. 

 The bank is essentially a rock formation over which 

 J water seeps throughout the year. The moss forms a 

 thin cover on the rocks, seldom being over an inch 

 or two in depth. The specimens were collected in 

 wet moss at the junction of one rock and another 

 where a slight niche was formed." The habits of the 

 adults have been described by Whitney (1947). 



A single species, Tanypteryx hageni (Selys) 1879, 

 has been described from western North America. 



Family CORDULEGASTRIDAE 



The family Cordulegastridae contains a single genus 

 in North America, although some workers split off 

 Taeniogaster Selys and Zoraena Kirby. 



Fig. 4:15. Wings of Tanypteryx hageni 

 (Needham and Westfoll, 1955). 



Genus Cordulegaster Leach, 1815 



A single species, Cordulegaster dorsalis Hagen 1858, 

 is widespread in western North America, being known 

 from Alaska to southern California along the Pacific 

 Coast, and eastward to Wyoming and Utah. Another 

 species, C. diadema Selys 1868, is known from Utah, 

 the Southwest, and northern Mexico, but it has not 

 been found in California. 



Adults of Cordulegaster dorsalis are very large 

 and are strong fliers. Kennedy (1917, p. 517) observes 

 that, "In the steep and narrow mountain gorges where 

 the rushing torrents pour down through the shade of 

 the redwoods and alders, this dragonfly adds a note 

 of mystery to the scene, for the individuals with their 

 strange ophidian coloration glide noiselessly up- 

 stream or down, never showing that curiosity toward 

 strangers or unusual surroundings which is exhibited 

 by the libellulines of the sunny valleys, but always 

 moving straight ahead as though drawn irresistably 

 onward. Only males are common on the streams, the 

 females seldom resorting to the water except to ovi- 

 posit. The males, as indicated above, fly on the 

 longest beats I have observed for any dragonfly, for 

 they fly continuously upstream or down until they 

 come to the head of the stream or to the slow water 

 below, or until some unusual obstruction turns them 

 aside, when they face about and fly as steadily in 

 the opposite direction. The course is usually a foot 

 or two above the surface of the stream and goes 

 through dense shade and any loose brush or foliage 

 which may hang over the water. Because of this habit 

 of flying in long beats this dragonfly is not easily 

 taken, as the collector has but a single chance at 

 each individual" (figs. 4:7). 



Regarding oviposition, Kennedy writes, "The 

 female flew hurriedly up the creek and every few 

 yards stopped, and with a sudden backing or down- 

 ward stroke, while hovering with the body in a per- 

 pendicular position, stabbed her large ovipositor 

 into the coarse sand beneath. Four to ten such per- 

 pendicular thrusts were made at each stop. Some 

 stops were along the open beaches, but more were in 

 quiet nooks between large rocks where she would 



