22 
Psyche 
[March-June 
angle of forty-five degrees, deeply sulcate medially, the sides 
swollen, rounded, without spines. 
Abdomen short oval, flat, vitreous, dark reddish brown on 
first, second and narrowly on base of third segment. Re- 
mainder bright orange. 
Legs dark shining purplish or reddish black, tarsi except 
hind basitarsi light yellowish brown. Fore basitarsi swollen 
anteriorly. Hind basitarsi considerably swollen. Hind tibiae 
greatly swollen and dorsally arcuate, a curious crease run- 
ning around it, below the part of greatest swelling. Tibiae 
heavily long black pilose. 
Wings brownish especially basally, with a faint pale yel- 
low spot beginning past the stigma. Last section of fourth 
longitudinal vein straight, not angular, no spurs present, 
not even from the angle of the fourth longitudinal vein. 
Length 7 mm. or about 8 mm. with the antennae. 
One male. Barro Colorado, Panama, July 16, 1924 
(Nathan Banks). Type in the Museum of Comparative 
Zoology. 
This remarkable species suggests Microdon panamensis 
Curran, which lacks the interesting structural characters 
of this form. It is a handsome and peculiar species, that 
like Ubristes resembles Trigonid, bees, but differs from that 
genus in the development of the vertex and scutellum, etc. 
Paramicrodon novus n. sp. 
Plate II, figs. 10 and 11. 
Female. Head very globular, front wide, almost hori- 
zontal, sides nearly parallel diverging slightly to vertex. 
Vertex from corner of eyes very suddenly and sharply 
widened so that the post optical vertex is wide and deep. 
Front and vertex slightly convex, their color shining brown- 
ish or black, with short abundant, upright, golden pile. Ocelli 
set far down the middle of the front, more than half way 
down from vertex (extreme) to antennae. Face more narrow 
than front, sides almost parallel, similar in color and simi- 
larly pilose. Antennae set a little above middle of face, 
wholly brownish orange, first and second joints short, sub- 
equal, third equal to first and second. Arista dark, thickened 
basally, half again as long as third joint. Eyes bare. 
