WATER-STRIDERS, STRIDULIVELIA—-DRAKE AND MENKE 419 
dark fuscous; antenna unicolorous; body beneath with some bluish 
luster. Length: 4.45-5.00 mm.; width: 1.50 mm. 
Antennal measurements: segment I, 1.25 mm.; II, 0.85 mm.; II, 
0.70 mm.; LV, 0.58 mm. Middle legs with tarsal segment II longer 
than If (58:54); hind femur (male) slightly incrassate, armed beneath 
with two rows of moderately large spines; tibia beneath with a double 
row of small, closely set teeth; trochanter with several dark fuscous 
teeth; female with hind trochanter unarmed, femora beneath without 
spines on basal part, the tibia with two rows of dark teeth; abdominal 
pleurites with vertical furrows on II-IV; male parameres as in plate 3,d. 
Macroprerous Form: Unknown. 
This species was described from a series of specimens taken among 
emergent vegetation in rivers near Puebla, Tampico, and Ciudad de 
Valles, Mexico, and is not recorded elsewhere. The characters in 
the key set it apart from other nonstridulating members of the 
subgenus. 
U.S. GOVERNMENT PRINTING OFFICE: 1962 
