45 



4. yEsr/uKf sp. {b). 



This species is represented in our collections by a quantity 

 of young nymphs, 5 mm. to 24 mm. long, all taken from rushes, 

 wood, etc., along the weedy margin of a lake in Yellowstone 

 Park, near Gardiner River, August 30. Unlike the preceding 

 species, which it closely resembles in structure, the hind angles 

 of the head are rounded, and the very young nymphs are banded 

 much as in Anax Junius but not on quite the same segments. 



5. ^iJsrhna califonu'ca Calv. 



^■E, californica, Calvert, '95. 



This is a species of the far West and the Pacific coast, not 

 found in Illinois. The nymph is here described for the first 

 time. A single one was taken from an irrigation ditch near 

 Tombstone, Arizona, and bred in May, 1897, by Mr. F. C. Wil- 

 lard. The exuvia and imago are now in the Cornell University 

 collection. Through the kindness of Dr. P. P. Calvert, Mr. 

 Needham has examined three young nymphs from the collec- 

 tion of the Academy of Natural Sciences, Philadelphia, which 

 appear to belong to the same species. 



The nymph measures 34 mm. ; abdomen 20 mm.; hind 

 femur 6 mm.; width of head, 7.5 mm., of al)domen 7.5 mm. 



The head is narrowed behind the eyes to the rounded hind 

 angles, between which are two pairs of scars, the smaller pair 

 on each side of the median line. The median lobe of the 

 lal)ium is not prominent; its border is without teeth, its median 

 cleft closed. The lateral lobes are truncate, but their external 

 angle is rounded off slightly. The supracoxal processes are 

 equal and divergent at almost a right angle. 



The lateral spines on the 6th abdominal segment are slen- 

 der and appressed, those on the succeeding segments increas- 

 ing regularly in length. The inferior abdominal appendages 

 are as long as segments 9 + 10, the laterals one half as long as 

 the inferiors; the superior a little shorter than the latter, 

 roundly notched as usual at the tip, and fringed with a row of 

 stout blackish bristles along either side. 



