NO. 2192. DRAOONFLIES, CALIFORNIA AND NEVADA—KENNEDY. 505 



Color No. IV. Postocular spots blue, legs still pink; thorax, sides 

 of 1 and 2 and dorsum of 8 and 9 blue. Sides of 3-7 yellow. In 

 this stage the postocular spots have become disconnected and much 

 reduced in size. The eyes previous to this stage have been pale green, 

 lighter below, but now the black cap is sharply indicated. The black 

 humeral line has become broader; the external line on the tibia is 

 heavier and an external line is appearing on the femur. This changes 

 into: 



Color No. V. Tliis is close to the "adult" stage described first. In 

 tliis final stage the postocular spots are becoming obscured by smoky, 

 the humeral line has widened until it has obliterated the pale ante- 

 humeral line, the blue spots on dorsum of 8 and 9 have been replaced 

 by black and the femora have become broadly black above. 



This final stage seems to be dimorphic, as some old females have the 

 pale areas green and some pure blue. Among the 75 CaUstoga females 

 I saw but two green females. 



Dr. Calvert ^ described a yellow form of the female of this species. 

 As he had dried material only, it is possible that his yellow form is 

 the same as this gi-een form with the blue factor of the green faded. 

 Some agrionines, greenish blue in life, fade to yellow in dried material. 



Nymjyh. — Described from a male nymph (alcoholic) collected at 

 Cahstoga, California, June, 1914. Deposited in the United States 

 National Museum. 



Abdomen (exclusive of gills), 6 mm.; gills, 5.5; hind femur, 3; 

 head, 3 mm. wide. 



Nymph (see figs. 64-69) of the usual ischnuran form with wide flat 

 head, short abdomen, long legs and acuminate gills. Antenna seven 

 jointed. Labium with four mental setae on each side and a row of 

 five setae on the lateral lobe. Wings reaching to the middle of 

 segment 4. Hmd femora reaching to middle of segment 4. The 

 abdomen tapering regularly to apex, with a weU-defined lateral keel 

 on segments 1-8. Genital valves of female reaching to beyond apex 

 of 10; the ventral edge with two small spines and several long hairs. 

 Gills widening to the apical two-fifths, whence they taper to an acu- 

 minate point. The inferior edge of the gill is straight from the base 

 with but shght taper for the first third, when the widening of the gill 

 mcreases rapidly to the apical two-fifths, as stated previously. This 

 first straight thhd of the interior edge is heavily spiculed while the 

 remaining portions of the superior and inferior edges are smooth, 

 except 8 widely spaced spicules on the base of the dorsal edge (see 

 fig. 69). 



The colors in this nymph were inconspicuous. This peculiar re- 

 striction of the spicules to the base of the gills distinguishes this 

 nymph from those of Ischnura cervula and I. perparva, in both of which 

 both edges of the gills are spiculate to beyond the middle. In both 



1 Biol. Cent. Amer., Neur., p. 127. 



