ART. 4. REVISION OF THE FAMILY THEREVIDAE—COLE. 47 
Amula, and Omilteme, all in Guerrero, Mexico, and was doubtful 
whether the species was distinct from notata Wiedemann. 
A male from Omilteme and one from Amula were loaned from the 
collection of the American Museum, and they seemed to represent a 
distinct species, much closer to haemorrhoidalis than to any other 
species; whether they are the true univittata or not it would be dif_i- 
cult to say, because of the many closely related species in this group. 
PSILOCEPHALA SIGNATIPENNIS, new species. 
Plate 8, figs. 93 and 103. 
Male.—Length 6 to 7.5mm. Head black; the face, a rim next to 
eye, cheeks, and lower corners of frontal triangle silvery white polli- 
nose; most of the frons shining black and erect black pilose. Pile of 
occiput and palpi white; cheeks with short black hairs on a black 
spot below the eye; occiput semishining grayish black, with black 
bristles. Antennae black, more or less gray pollinose, especially the 
first two joints which are black bristled; a noticeable group of short 
black bristles at base of third joint. (Fig. 93.) 
Thorax black, the large median portion gray pollinose, the sides 
and three narrow dorsal stripes semishining; pile of the dorsum erect 
and black. Scutellum black, semishining, the tip whitish, with four 
black bristles. Pleura black, the pteropleura shining, the rest and the 
coxae silvery gray pollinose and white pilose. Halteres entirely black. 
Abdomen black, the dorsum of second to sixth segments shining 
silvery pollinose with sparse, fine white pile; first segment gray polli- 
nose with rather long white pile at the sides; the lateral margins of 
the first, third, and fourth segments shining black, also the anterior 
part of the second and the venter, except faint gray pollen on the 
first two segments; pile of abdomen largely white, some black below 
on the sixth segment and on the genitalia. Genitalia mostly con- 
cealed in the last abdominal segment, brown and yellow in color with 
yellow pile above. (Fig. 103.) Legs in most specimens entirely 
black, femora with most of pile silvery white and erect; front femora 
with three black bristles inside and below. Wings whitish hyaline, 
stigma black, apex of wing usually gray, and a large brownish gray 
spot near the end of cell first M—2 which varies somewhat in size; cell 
M-3 closed near the margin. 
Female.—Nearly like the male. Frons shining black and nearly 
the same as jn the female of platancala; a small round depression 
just above and between and antennae and a depressed line above this. 
Cheeks below the eye dull black. 
Mesonotum with very short reclinate black pile. Abdomen shining 
_black, short reclinate black pilose on the first, second, and third seg- 
ments, the rest of the abdomen and the genitalia short erect black 
