26 DIPTERA 
2. Inner flexor edge of hind femora with a series of strong 
spinigerous tubercles, the corresponding surface of hind 
tibiis concaveand margined. .—. . 2. s eo WS UE NE 3; 
Femora not armed with conspicuous spinigerous tubercles, : 
the hind tibiz not excavated nor prominently edged. . . . . . . . . . . . . E 
3. The stout tubercles of inner flexor edge of hind femora 
arising near middle of the hind tibie, as seen when , 
inflexed, and extending quite to the knee; hairs of thorax 
dark; basal half of wing infumated . . . . . . . E. PuRPUREUS, Walker. 
The stout tubercles not extending nearer the knee than the 
basal third of the hind tibie; hairs of thorax yellow . . . . . . . . . . . . . 4- 
4. Five to seven strong tubercles present; wings hyaline. . . . . . . . . . . . . - f 
But a single stout tubercle present . . . qr e P EALLR ME UN rule ee ye 
5. Principal tubercles of hind femora deii on a crested 
swelling opposite middle of tibia; thorax jet black . . E. srRUMATICUS, nov sp. (1). 
Tubercles separated, opposite basal third of tibia which 
bears a pair of distally directed dicc thorax 
vioaceous . . . . DRM ace : . E. ocREATUS, nov. sp. (2). 
6. Hind tibie with s CORE tibeicio on extensor sido: 
wingsclet ... . 2. 2 27 Vo. 7v 1.5, V 0. VRREUDICRUS SONA OR 
(1) Euhybos strumaticus, nov. sp. — Male, Length 3 mm. Black, without metallic tinge, anterior tibiae and 
hind knees brown, basal two joints of the tarsi yellow; hind femora with a row of strong spine-tipped tubercles; wings 
hyaline. Third joint of the antennae bluntly oval, two and one-half times as long as broad and one-third as long as the arista, 
Hairs of the notum moderately abundant, long, yellow, scutellum with two bristles and a few small hairs. Upper valve of 
the pygidium longer than wide, continued as a long broad process which furcates and straddles the terminal valve, the 
terminal valve tipped with a fringe of curled yellow hairs, right side of the lower valve bearing along process which is 
broader at the middle and is fringed posteriorly with long curled yellow hairs. Middle tibiz with about five moderate 
extensor bristles and a long apical yellow bristle within, anterior tarsi with long yellow flexor bristle toward the base, and an 
apical brown extensor bristle, hind trochanters with thorn-like spine, hind femora very robust and spinose beneath, the spines 
growing from small tubercles which are stronger along the apical third, seven of those of the inner flexor edge grouped on a 
swelling and bearing very robust but short spines, this cluster corresponding to about the middle third of the tibia which 
is excavated and sharply margined, Halteres black. Wings hyaline or with very faint uniform brown tinge, stigma very 
weak but filling out the marginal cell, costal cell narrow and straight in front. 
Female, Thefemales supposedly of this species have the abdomen ending in a curious ovipositor and lack the heavy 
armature of the legs. The eighth segment is elongate, bearing near the middle on each side a strong backward-projecting 
spur, before which the segment is depressed and trapezoidal and beyond which the segment becomes more or less tubular. 
Type : Plummer' s Island, Maryland, R. C. Shannon, collector, in the U. S. National Museum. Paratypes from 
South Carolina, Georgia, Alabama, Louisiana and Texas. 
(2) Euhybos ocreatus, nov. sp. — Male. Length4 mm. Black, notum and tergum violaceous, tarsi yellow. 
Outer antennal joint oval, two times long as wide, arista two times antennal length ; occiput brownish gray. Notal hairs 
yellowish in front, dark behind, apical scutellars strong, three lateral hairs on scutellar margin. Hairs at base of abdomen 
long and yellow as usual ; pygidium small, upper valve ending on left side in a flat hook and on the right side in two ribbon- 
like processes, lower valve ending in a long ribbon-like process, Front tibize with a small pimple on basal third of flexor side, 
middle tibiae with three outstanding setze, hind femora strongly spinose beneath, four or five spines arising from strong 
close-set tubercles toward the knee opposite a flat expansion at basal two-fifths of the tibia. This expansion projects 
distally on each side as a prong and beyond it, near the middle of the tibia, is a distinct bend. The flexor surface of the 
tibia from the bend to the apex is concave, with an edge along each side. Hind metatarsi with two long fine dorsal sete ; 
last three tarsal joints and apex of claws black. Wings narrow, clear hyaline, stigma distinct and brown, veins thin, discal 
cell very long, the sections of fifth vein 4 : 1. 
Female. Seventh abdominal segment transversely creased at base, then semicircularly bulged and compressed at 
apex, ovipositor long. Legs normal, two anterior and one superior bristle near hind knees. Stigma faint, discal cell shorter. 
One specimen of each sex, La Suiza de Turrialba, April, 1922, Pablo Schild, collector. 
(3) Euhybos verruclorus, nov.sp. — Male. Length 5 mm. Black, the anterior legs and hind tarsi yellowish 
brown with last three joints of all tarsi blackish. Occiput lightly cinereous; last antennal joint conical, two times as long 
