84 Psyche [June
no reason to suppose that the development of the entomophilous
flora would have varied in any respect had entomophily never
arisen among the Coleoptera.
TABLE OF NORTH AMERICAN SPECIES OF THE DIP-
TEROUS GENUS THRYPTICUS, WITH DESCRIP-
TIONS OF FOUR NEW SPECIES.
By Millard C. Van Duzee,
Buffalo, New York.
While studying the Thrypticus in my collection and a little mate-
rial that came to hand I found four forms that seem to be new.
These are described below.
In wilUstoni Wh. the fore and middle coxse may be mostly
yellow or infuscated almost to the tips, while in the female they
may be somewhat blackened. This seems to be our most abun-
dant species in western New York. I have seen examples from
New England; Toronto, Ont. ; and Columbia, Mo. I have taken
a number of T. fraterculus Wh. at Lewiston, N. Y., and have seen
a series of eight from Berkeley-Hills, Cal.; Professor Aldrich re-
ports it from Mexico.
The species of Thrypticus are minute flies of bright metallic
color with a concave area in front of the scutellum and with the
bristles and hairs of the thorax and abdomen yellow; the third
and fourth longitudinal veins are usually convergent at tip, but
sometimes parallel, and the hypopygium is flexed under the
abdomen, often reaching nearly to the thorax.
The hypopygia of the males of those species I have examined
are very similar. There is a large capsule or outer part which is
covered with scales of pollen that are always inclined backward.
Its appendages are lamelliform with a pair of slender processes at
their base in most species (these seem to be lacking in ivillistoni).
There is also a central filament (the penis) which originates on
or near the base of the hypopygium and usually extends nearly
to the end of the lamellae; this filament is inclosed in a sheath which
is shorter and often so closely applied to it that the two appear
to form one piece. In the drawing of aurinotatus sp. nov. this
filament does not show as it was folded under the abdomen.
BioStor
