104 Bulletin Wisconsin Natural History Society. [Vol. 6, Nos. 1 — 2. 
3. Hind wings with fuscous streaks restricted to space within the 
level of the first antenodal cynosura 
Hind wings with the fuscous more distributed, not in isolated 
streaks, reaching be3'ond the level of the first, and generally 
to the fourth antenodal semiaquea 
Taking the triang-le of the hind wing, whether crossed or free, as 
a specific character, it is well to mention that this by no means is a 
constant factor for determination. In the collections of the Public 
^Museum I have seen specimens of cynosura with the triangle free, and 
of spin if/era- with the triangle crossed. 
Tetragoneuria spinigera Selys, Bull. Ac. Belg. 31 (2), p. 269, 1871 ; 
Needham, Bull. 47, X. Y. State Mus.. p. 493, 1001 (Bibliography). 
Abd. male 30—33, female 32 ; h. w. male 29—33, female 32—33. 
]Male. — Brown, marked with black and yellow. Face yellow, a 
greenish transverse band below the frons. Frons above with a promi- 
nent black T-spot. Thorax brown, dorsal stripes, meral and lateral 
sutures black. Generally these markings are hidden below the thick 
gray pile. Legs black, fore femora brown. Wings hyaline, nervure 
black, costa and stigma brown. Fore wings with the extreme base 
fuscous, hind wings with streaks along the median vein and the anal 
angle. Abdomen with segments 1, 2 and the base of 3 brown. Seg- 
ment 2 is dilated, 3 slightly constricted, 4 — 9 flattened. Dorsum black, 
wider apically, lateral yellow spots on 2 — 9. Appendages black, the 
superiors with an inferior spine at the basal third. 
The female is similar. 
Life Zone : Transition and Upper Astral. 
Wisconsin : ^Milwaukee County, June 1900 ; Dane Countv, May 
1900 ; Vilas Co., Divide, June 24-30, 1907. 
Time and Habitat' — June to July about lakes and in forest clear- 
ings. 
Tetragoneuria cynosura Saj-, Journ. Ac. Phila. 8, p. 30, 1839 ; 
Hagen, Syn. Neur. N. Am., p. 139, 1861 ; Needham, Bull. 47 N. Y. State 
Mus., p. 494, 1901 (Bibliography). 
Abd. male 28—39, female 27 ; h. w. male 28, female 29. 
Male. — Differs from the preceding species mainly by the absence of 
a T-spot on the frons and by its smaller size. The abdominal appen- 
dages are curved, touching at the middle the apices thickened. 
The female is similar, the vulvar lamina exceeding the sternum 
of 9 in length, bifid. 
Life Zone : Transition and Upper Austral. 
Wisconsin: Milwaukee Co., June 4, 1899. 
Time and Habitat — May to July about smaller waters (ponds and 
creeks). 
Tetragoneuria semiaquea Burmeister, Handbuch der Entomologie, 
2 p., 858, 1839; Llagen, Syn. Neur. X. Am., p. 140, 1861; Needham, Bulk 
47 N. Y. State Mus., p. 494, 1901 (Bibliography). 
Abd. male 26—27, female 28 ; h. w. male 26—28, female 29. 
]\Iale and female. — This species resembles cynosura greatly. The 
chief distinction is that the fuscous of the hind wings is more suffused, 
always extending at least beyond the second antecubital. 
Life Zone : Transition and Upper Anstral. 
Wisconsin : Dane Co., June 2, 1900. 
Time and Habitat — May to July about smaller waters. 
