48 NEUROPTERA. 
a. Each mesepisternum with a small, superior, antehumeral, metallic green spot 
(young), or entirely black (in old age). Superior appendages of the male 
with an obtuse basal tooth, the median dilatation straight, terminating 
posteriorly by a distinct emargination or angle; inferiors somewhat 
S-shaped, divergent at tips, more than half as long as the superiors, 
reaching beyond the median dilatation thereof. . . . . . . . - . & sigma. 
aa. Each mesepisternum with a metallic green stripe one-sixth (or less) as 
wide as the mesepisternum itself, upper end usually a little widened. 
Superior appendages of the male with an acute basal tooth and a convex 
median dilatation on the inner side; inferiors almost as long as the 
superiors, reaching beyond the level of the apex of the median dilatation 
thereof. 2. 2. 1. ww ew ee ee ee ee ee www A forficule. 
aaa. Hach mesepisternum with a metallic green stripe one-third to one-fourth as 
wide as the mesepisternum itself, of nearly uniform width. Superior appen- 
dages of the male with the basal tooth not acute, median dilatation less 
convex; inferiors short, one-half as long as the superiors, not reaching to 
the apex of the median dilatation thereof. . . . . . ... . . . &5. tenuatus. 
N.B.—Post-mortem discolorations occur frequently in estes, as in all pale- 
coloured Agrionidz, and are liable to induce one to take them for natural black 
markings. Their true character is to be recognized by their usual asymmetry on the 
two sides, their slightly paler hue when compared with undoubted black marks, and 
by comparison of a series of individuals of the same species. 
1. Lestes alacer. (Tab. III. fig. 26.) 
Lestes alacer, Hagen, Syn. Neur. N. Am. p. 67 (1861) '; Selys, Bull. Acad. Belg. (2) xiii. p. 304 
(1862) °; Kirby, Cat. Odon. p. 161 (1890) *. 
Hab. United States, Arizona (C. U. lot 35, M.C. Z.: 1 3, 8 2), San Gerdnimo, 
New Mexico (Gulick, P. P. C. det.), Pecos River! 2 and Round Mountain, Blanco Co. 
[6 3 |, Texas [1 ¢,19] (A. N. S.).—Mexico, Tlalnepantla (Barrett, coll. P. P.C.: 
13, 12, teneral), Tacuba (coll. McLachlan: 1 3,12; Barrett, coll. P.P.C.: 
1 adult 9, 1 teneral ¢ ), city of Mexico (Dr. Rogers, M.C.Z.: 13; Forrer: 1 3; 
H. H. Smith: 4 2), Santa Fé [1 3], Eslava [1 3 ] (Barrett, coll. P. P. C.), Uruapam 
in Michoacan (coll. Deam: 2 2), Cholula (coll. Deam: 1 2), Cuernavaca (Barrett, 
coll. P.P.C.: 1 @), Orizaba? (H. H. Smith & Godman: 1 9); Guaremana, Guate- 
mala city 5000 feet (Salvin, coll. McLachlan: 1 3,19; M.0.Z.: 128,12). 
Hagen ', followed by de Selys?, speaks of the sides of the thorax having “a broad, 
fuscous, middle fascia.” In 1899, I examined Hagen’s type, a male from the ‘“‘ Pecos 
River, Texas,” now in the Museum of Comparative Zoology at Cambridge, Mass., and 
came to the conclusion that this marking was probably due to discoloration after 
death, especially as I have observed similar dark post-mortem bands on some perfect 
males of the present material. The abdomen and both front wings of the type have 
