1933 ] 
Notes on Hippoboscidx 
101 
NOTES ON HIPPOBOSCIDAE 
7. A TENTATIVE KEY TO THE SPECIES OF 
OLFERSIA WIEDEMANN ( FERONIA LEACH; 
PSEUDOLFERSIA COQUILLETT). 
By J. Bequaert 
Department of Tropical Medicine, 
Harvard Medical School, Boston, Mass. 
A prolonged study of extensive material has led me to 
recognize more species of Olfersia than is customary at pres- 
ent. Pending the more detailed publication of my results, 
I offer herewith a key to the species which I regard as valid. 
Full acknowledgments will be given later; but I wish to 
thank now Prof. G. F. Ferris for entrusting me with his 
entire collection of the genus, as well as Mr. J. E. Collin for 
the detailed study of Bigot’s types which he made at my 
request. 
Key to Species 
1. First basal cell (R) short and wide, distinctly bulging 
before the apex; fourth longitudinal vein (M 1+2 ) partly 
setulose. First tergal plate of abdomen triangularly ex- 
cised at apex in male, divided into two median lobes in 
female 0. sordida Bigot. 
First basal cell (R) long and narrow, its apical half 
parallel-sided or 'nearly so; fourth] longitudinal vein 
(Mi + 2 ) bare throughout. Apical margin of first tergal 
plate straight or slightly curved inward 2. 
2. Posterior orbits (above eyes) about as long as or barely 
shorter than the greatest width of the inner orbits; 
occipital margins of posterior orbits and of postvertex 
(or vertical plate) strongly produced behind and sep- 
arated from one another by deep curved notches. Lower, 
frontal area of postvertex alutaceous, separated 
from the upper, smoother area by a slight transverse 
depression 3. 
