204 NEUROPTERA. 
prothorax bilobed, sectors of arculus of front wing arising from, 
or not from, a common stalk. 
Z. Eyes with no extension on the posterior margin. 
a. Discoidal triangle of front wing moderately wide, its anterior 
side about one-half as long as its proximal side, with which 
it forms nearlya right angle; males with the genital hamule 
two-branched. (The two species belonging to this fauna have 
an additional transverse carina on abdominal segment 4) . SyMPETRUM. 
aa. Discoidal triangle of front wing narrow, its anterior side 
about one-third as long as its proximal side, with which it 
forms an obtuse angle; males with genital hamule un- 
branched and inferior appendage almost as wide at apex 
as at base; abdominal segment 4 with no additional 
transverse carina... 0. + ee ee ee ee +) 6 Cannacria”, 
ZZ. Eyes with a slight convex extension on the posterior margin 
somewhat recalling those of the Cordulinew, abdominal seg- 
ment 4 with an additional transverse carina, males with 
genital hamule unbranched and inferior appendage much 
narrower at apex than at base. PLATYPLAX. 
XX. Spines on the third tibia 5-10 in each row, stout ; sectors of 
triangle of hind wing separated at origin, sectors of arculus of 
front and hind wings arising from a long common stalk, genital 
hamule of male two-branched. 
b. Subnodal sector and supplementary sector next below separated 
from each other by one row of cells, vulvar lamina of female 
projecting at a right angle to the abdomen; front wing with 
two cells between postcostal vein and hind margin at level of 
lower end of arculus; hind wing with the two post-triangular 
rows increasing to three at or distal to the level of separation 
of principal and median sectors and with one cell between 
the posterior angle of the triangle and the distal subbasal 
sector (A, of C.& N.) opposite. . . . . . . . CE RytHeMts. 
bb. Subnodal sector and supplementary sector next below separated 
from each other by two rows of cells, vulvar lamina of female 
not projecting ; front wing with three cells between postcostal 
vein and hind margin at level of lower end of arculus; hind 
wing with the two post-triangular rows increasing to three 
proximal to the level of separation of principal and median 
sectors and with two cells between the posterior angle of the 
triangle and the distal subbasal sector opposite. . . . . . Lerrnemis. 
* Cannacria and Sympetrum closely approach each other; the differences in number of the antenodal and 
postnodal cross-veins given by Mr. Kirby do-not distinguish them. C. furcata on the one hand, S. madidum 
and S. semicinctum, e.g., on the other, break down this distinction. 
