E. B. WILLIAMSON 
223 
Abdomen rod; segment one with a large squarish basal dorsal black spot and 
an oblique stripe on the sides below; sides of two yellowish, dark brown at base, 
this produced backward nearly or quite the length of the segment in two bars, 
one slightly above the lower edge, the other at about two-thirds the height of 
the segment; a similar single dark bar just above the narrow pale yellow lower 
border on three; more or less definite traces of the same on four and five; 
sides of eight and nine largely, and the apex of ten, dark brown, shading out 
above; a more or less distinct subaj)ical dark sj)ot on either side of the dorsum 
on eight and nine; median apex of ten black, shading out anteriorlj’, reaching 
nearly the base. Wntral suture black. Superior appendages black above, 
remainder reddish brown, lower edge darker; inferiors dull reddish yellow. 
Legs pale brownish yellow, outer surface of femora dark, black on the first 
two pairs, shading out basally, encircling the femur apically, the angle between 
the anterior and posterior faces narrowly yellow; anterior outer face and inner 
face of tibiae of first two j)airs largely black; tooth on tarsal claws well de- 
veloped, larger than in sylvalica or mariatia. 
Wings clear; stigma brown, covering veiy slightly less than one cell, its 
length about two and one-half times its width. 
Type. — Brazil: Rio Grande do Sul, (H. Ihering), cf, Coll. 
Acad. Nat. Sci. Phila. This and one other male is the material 
listed by Calvert as N. ruhriventris.'^ Only one of the specimens, 
designated as the type, has been seen by me. Dr. Calvert writes 
that the two are identical. Named for my sister, Ethel, wife of 
J. E. Merriman. 
Ethela, sylvatica, mariana and denticulata are four closely re- 
lated species. In ethela the appendages are scarcely separated 
from sylvatica, the differences minute and possilih' disappearing 
in a large series. The outer branch or angle of the lower part or 
division of the superior appendage, in interno-posterior view, in 
ethela is a symmetrical triangle; in sylvatica the upper edge is 
concave, the lower edge convex and the branch itself is narrower. 
The same view of the inner face of the upper part of the superior 
shows slight and scarcely definable differences in the two species, 
and there are many identical, even minute, details, such as, for 
example, a slight trough-like vertical depression across the 
surface just posterior to the lower beak-like termination of the 
surface, this beak-like termination resting just above and inner to 
the inner angle of the lower branch of the superiors, and identical 
in the two species. However, in this view of the’appendages 
the upper and lower edges of the inner face of the upper part of 
^Ann. Carneg. Mus., vi, p. 212, (1909). 
TRANS. AM. ENT. SOC., XLIII. 
