LESTES. AY 
been lost, so that a positive identification is no longer possible. I compared it with 
the individuals from Arizona, cited above, to which Haven had given the manuscript: 
name of L. fasciatus, and believed them to be identical. The type of L. alacer has 
nine postcubitals; their number in the series before me varies from ten to fourteen. 
The extremes in the variation in size are not associated with geographical distribution, 
so far as the present material is concerned. Abdomen, 3 29-36, 9 28-35°5; hind 
wing, ¢ 20-24, 9 21-25 mm. 
2. Lestes simplex. (Tab. III. fig. 24.) 
Lestes simplex, Hagen, Syn. Neur. N. Am. p. 68 (1861)*; Selys, Bull. Acad. Belg. (2) xiii. p. 298 
(1862) ?; Kirby, Cat. Odon. p. 160 (1890) °. 
Hab. Unitep Svrates?, ‘Texas *}22—Mexico!, Xucumanatlan [1 3], Amula [4 ¢, 
2 2], and Chilpancingo [1 ¢ ], all in Guerrero, 4600-7000 feet (H. H. Smith). 
Postcubitals on the front wings 11-14. Abdomen, ¢ 28°5-36, 9 32-33; hind 
wing, ¢ 20-24, 2 23 mm. It is worthy of mention that the upper and lower 
extremes of size for the males are all from individuals taken at Amula in August. 
L. simplex is closely related to L. forcipatus, Rambur, of the United States, which 
it probably replaces in Mexico. I have seen many specimens of L. forcipatus from 
Texas, and it is quite possible that it may be found in Northern Mexico also. 
3. Lestes sigma, sp.n. (Tab. III. fig. 33.) 
g. Labium yellow; face pale, perhaps blue in life, but the vertex, frons, and nasus becoming black with age. 
Thorax yellowish, a small, superior, antehumeral, metallic green spot; an isolated metallic green stripo 
on the mesepimeron, constricted at its middle ; a black spot on the lower end of the metepimeron and on 
the adjoining part of the metasternum. In the old male the entire thorax is black, pruinose, but the 
mid-dorsal thoracic and latero-ventral metathoracic carinw have each a fine yellow line. Femora pale 
(yellow or green), with three black lines which are superior, anterior, and inferior respectively. Tibie 
pale above, black below; tarsi black. Abdomen dark metallic green, becoming black with age ; segments 
3-7 with a basal, dorsally-interrupted, transverse, blue ring, 3-6 with a similar apical blue ring; sides 
of 3-7 blue, except where the dorsal black is dilated and extends down on to the sides in front of 
the apices of the segments; on the side of 7 the blue (or yellow ?) is confined to the basal half of the 
segment. 
Superior appendages longer than segment 10, about equal in length to 9, curved throughout their entire 
length ; basal fifth on the inner margin of each appendage with a rounded tooth very similar to that of 
L. tenuatus, and whose apex is scarcely more acute; following this tooth, the width of the appendage is 
considerably lessened, the inner margin showing an almost straight edge not visibly denticulated except 
under a compound microscope ; at half the length of the appendage this straight edge terminates abruptly 
at an angle of more than 90°, the width of the appendage being further lessened, but in the terminal 
third increases again, the apex being somewhat obliquely truncated with rounded angles. Viewed in 
profile, the superiors are nearly horizontal in the basal half, bent downward in the apical half at an angle 
of about 120° with the basal half. 
Inferior appendages about two-thirds as long as the superiors, slender, tapering gradually from base to apex ; 
in dorsal view they are divergent in the basal fifth, then convergent in the greater part of their length, 
* Is this an error in copying? I found no L. simplew in the M.C. Z. 
BIOL. CENTR.-AMER., Neuropt., December 1901. h 
