1908] 
Mi(ttJxOivsJci, Dragon Flies of Wisconsin. 
101 
carina near the front edge, and a lateral spot of yellow. The ap- 
pendages of the male are thickened at the apical half and without 
an inferior angle. 
HELOCORDULIA Needham, Bull. 47, N. Y. State Mus., p. 495, 1901. 
In the paper referred to Dr. Needham has discussed the char- 
acters upon which he based the separation of Helocordidia from 
the preceding genus, N curocordiilia. Besides the characters men- 
tioned in the table. Dr. Needham has noted several others when 
comparing Helocordnlia to its prototype, N eiirocordidia and to its 
nearest ally, Tetragoneuria. Such differences are : 
a. HELOCORDULA — Hind wing-s with six antenodals and free 
triangies. fore wing's with a single cross-vein in the triang"le. 
NEUROCORDULIA — Hind wings with five antenodals and triang-les 
crossed once, twice crossed in the fore wing's. 
b. HELOCORDULIA — Snb-triangie present, two cross-veins nnder the 
stig-ma. six antenodals in the hind wings, 
TETRA<10\EURJA—Sx\h-trLang]e absent in hind wing-s, a single 
cross-vein nnder the stigma, four antenodals in the hind wings. 
The two species may be separated by their genitalia : 
Male superior abdominal appendages with a distinct inferior tooth 
before the middle, the apex thickened, hairy; female vulvar 
lamina nearly one-half the length of 9, deeply bifid, divari- 
cated selysii 
Male superior abdominal appendages without a distinct inferior 
tooth, the apex thickened, naked ; female vulvar lamina less 
than one-third the length of 9, emarginate, the points widely 
divaricated, the lateral margins sub-parallel uhleri 
Of these two species Llilcri alone has been taken as far west as 
Ontario, and there is some possibility^ of finding it in the middle por- 
tions of the State, 
SOMATOCHLORA Selys, Bull, Ac, Belg, :n (2), p. 279, 1871; 
Needham, Proc, U. S, Nat. Mus, 26, p, 741, 1903 (Venation), 
About 40 Species of this genus are known. Our American 
species inhabit chiefly the colder life areas, few species as yet be- 
ing taken in regions w^armer than the Upper Austral. For Wis- 
consin we have only a single record of a species by Hagen. But 
the remarkable similarity of the fauna of northern Wisconsin to 
that of the White Mts. of New Hampshire leads us to expect the 
presence of a similar number of species in the mountainous por- 
tions of our state. The different species are greatly alike in color 
and pattern of the markings. They are separated chiefly by the 
form of the superior abdominal appendages of the male. Accept- 
ing the superior appendages as criterion; the five New Hampshire 
species have the following points of difference : 
tenehrosa — apical half abruptly incurved, directed downward, a 
superior tooth at the deflection; inferiors recurved, furcate. 
