PLATHEMIS 229 
the first abdominal segment. There are three yellow spots in a vertical 
row on the occipt behind the eyes. The genus is otherwise similar to 
Libellula. 
The nymph (Ndm. ’01, p. 536) is like that of Libellula except that 
the head is widest behind the eyes, and the front border of the median 
lobe of the labium is crenulate. 
KEY TO THE SPECIES 
Adults 
Male with a median cross band on the wings of a uniform brown 
PalOES. Be TNtee Outi Malese (hh. Mlle cher od puede ad 8 lydia, p. 229 
Male with a median cross band on the wings divided by a paler 
Poet Aer REMY CRE ORES UR eg OE ENP subornata, p. 230 
207. Plathemis lydia Drury 
Drury 1773: Mtk. Cat. p. 142: Ris ’10, p. 261: Howe ’20, p. 74: Garm. ’27, p. 255. 
Syn: trimaculata De Geer. 
Length 47 mm. Expanse 68 mm. N. F. and B. C. to Ark., N. C. and Calif. 
A very common and widely distributed species in which the wings of the two 
sexes differ markedly in coloration. Face and vertex yellowish brown, shining, 
with a broad black stripe between. Occiput brownish. 
Thorax obscure brownish, clothed with short pubescence; 
sides blackish inferiorly and marked by two very oblique 
yellowish white streaks that are very variable in distinct- 
ness and some times interrupted where they cross the 
suture, best defined at their lower end and tapering up- 
ward. Legs brownish, darkening with age; tarsi and spines 
blackish. Wings with a conspicuous pattern of brown, dif- 
fering in the two sexes, as shown in the figures on p. 200. 
Behind the broad basal spot of the hind wing of the male, a 
large chalky white triangle develops with age. Abdomen 
brown, slowly tapering beyond segment 3 in the male, 
parallel sided to 8 in the female, showing a row of oblique 
pale spots low down on sides of segments 3-9. These are 
less distinct in the male and become wholly obscured with 
age by pruinosity. 
hia ite “Common from April to October, having the longest 
nymph of the seasonal range of any of our dragonflies” (Brimley ’03, p. 
Whitetail. skim) (2092 0 pp oun 
mer, Plathenas “This species is a constant companion of L. pulchella. 
lydia. Often they have a definite beat along some bend in the 
shore or around beds of bulrushes where they race up and 
down the banks, now and then meeting with a rustle of wings” (Whed. ’14, p. 
100). 

