ARCHILESTES.—LESTES. 47 
me at present seem to show ¢ that they are, on the whole, rather smaller than those 
on the mainland. Still, too much emphasis must not be laid on this, for in the present 
material from Cuernavaca alone the dimensions are quite variable:—Abdomen, g 49- 
43, 9 42-41; hind wing, ¢ 38-32, 9 37 mm. No differences in size or in other 
features seem to separate the individuals from Guatemala and Costa Rica from those 
of Mexico *. 
LESTES. 
Lestes, Leach, Edinb. Encye. ix. p. 187 (1815); Selys, Bull. Acad. Belg. (2) xiii. p. 295 (1862) ; 
Kirby, Cat. Odon. p. 160 (1890). 
A cosmopolitan genus, of which at least sixty-five species have been described. 
Those of the present fauna may be distinguished as follows :— 
I. Rear of the head black, yellow around the occipital foramen. Dorsum of the 
thorax green or yellow, with a broad median black band, each half of which 
is two-thirds as wide as its respective mesepisternum, and is contiguous with 
the mid-dorsal carina. Inferior appendages of the males about two-thirds as 
long as the superiors. 
a. Mesepimeron and metapleuron yellowish, no black bands. Superior appen- 
dages of the males having on the inner side an acute basal tooth, and a 
convex median dilatation terminating posteriorly by a distinct emargination 
or notch when viewed from above ; inferior appendages straight (seen from 
above), usually inclined towards each other, curved upwards so that the 
upper edge (seen in profile) is concave. . . . . . + . . . . « I. alacer. 
aa. Mesepimeron yellow, with a black band on the posterior half for its entire 
length; metapleuron pale, but usually with some black, especially along 
the second lateral suture. Superior appendages of the male having on 
the inner side a basal tooth, and an almost straight median dilatation 
terminating posteriorly without any distinct notch or emargination ; 
inferiors curved slightly towards each other, especially near the tip; seen 
in profile, straight or curved slightly downward so that the upper edge 
is convex . . . 2 simplex. 
II. Rear of the head yellow, although becoming black ir in very ‘old individuals of 
L. sigma at least. Dorsum of the thorax with a metallic green spot or stripe 
each side, which is not contiguous with the mid-dorsal carina. (In very old 
individuals of L. sigma the entire thorax is black and pruinose.) A metallic 
green stripe also on the mesepimeron. 
* A female from Guadalajara has the right front wing malformed, in that it is shorter (33 mm.) than the 
normal left (39 mm.), slightly longer (15 mm.) from base to nodus (13 mm. in the left), the reduction 
occurring beyond the nodus as well as an abnormal widening (94 mm. compared with 8), the nodal sector 
interrupted for five cells, a supplementary sector being inserted between the first and second sectors of the 
triangle and one between the second sector of the triangle and the hind margin; various other minor 
irregularities in the venation exist. 
