VOLUME 55, NUMBER 1 
49 
ventrally, broadly annulated with dark brown beyond middle, dark on distal 
one-fourth. Measurements of legs: 
Femur 
Tibia 
Tarsal 1 
Tarsal 2 
Tarsal 3 
Anterior 
77 
73 
2 
3 
9 
Middle 
117 
123 
2 
36 
39 
Posterior 
113 
112 
3 
25 
25 
Length, 4.75 mm, width (across humeral angles), 1.6 mm. 
Macropterous female. —Very similar to male except legs and antennae 
lighter colored. Armature of posterior femur less pronounced; 3-4 small 
basal black spines, one slightly larger spine past middle and 5-6 smaller 
spines beyond; anterior row consisting of 8-10 small black spines reaching 
from basal one-third to distal end. 
Length 4.65 mm, width 1.6 mm. 
Material examined .—MEXICO: Holotype, macropterous S, and allo¬ 
type, macropterous $, Chiapas, 11.2 km (7 mi) N of Arriaga, CL1246, XII- 
18-1969, J. T. Polhemus. Paratypes as follows: Chiapas, about 600 macrop¬ 
terous 6 6 and $ $, same data as holotype; 1 macropterous S, Veracruz, 
12.8 km (8 mi) NE Tlapacoyan, VII-16-1969, A. S. Menke (paratype of 
Velia phriatra Drake and Menke; manuscript name); 120 macropterous 
6 6 and $ ?, Chiapas, W of Rizo de Oro, CL1331, 1-14-1970, J. T. Polhe¬ 
mus. 
This species is closest to pueblana Drake and epeixis Drake and Menke. 
In the Drake and Menke key, the males of secerna will key to pueblana 
and the females to epeixis on the basis of the vertical furrows on the ab¬ 
dominal pleura. The whitish last antennal segment given as a key character 
by Drake and Menke is not consistently diagnostic, because some specimens 
of all four species of the subgenus Aenictovelia have the last antennal seg¬ 
ment yellow brown to whitish. 
The tumid and posteriorly truncate male seventh abdominal sternum of 
secerna immediately separates it from all other species of the subgenus. 
Also, in secerna the metasternum in side view is highest medially, sloping 
posteriorly, whereas in the other three species the metasternum is highest 
at the posterior margin and is truncate posteriorly. 
Literature Cited 
Drake, C. J. 1951. New water-striders from the Americas. Rev. de Entomol. 22: 371-378. 
Drake, C. J. 1957. New Neotropical water-striders. Proc. Biol. Soc. Washington 70: 111- 
118. 
Drake, C. J., and H. M. Harris. 1938. Veliidae y Gerridae Sudamericos. Notas Mus. La- 
Plata 3: 199-204. 
Drake, C. J., and H. M. Harris. 1941. A new Velia from Trinidad. Rev. de Entomol. 12:338-339. 
Drake, C. J., and A. S. Menke. 1962. Water-striders of the subgenus Stridulivelia from Mex¬ 
ico, Central America and the West Indies. Proc. U.S. Nat. Mus. 113: 413-419. 
