I 
G-. F. Ferris and F. R Cole 201 
Genus Stilbometopa Coquillet. 
Stilbometopa impressa (Bigot). 
Figs. 17, 18. 
1885. 01 fersia impressa Bigot, Ann. Soc. Ent. France, p. 257. 
1902. Stilbometopa impressa (Bigot), Speiser, Zeitschr. f. syst. Hym. und Dipt. ir. 163. 
Previous Records. Originally recorded by Bigot from California and 
recorded by Speiser from a specimen from California. 
Specimens Examined. A female taken from “valley quail,” Lophortyx 
californica, California, in the collection of the California Academy of Sciences; 
one female from Mecca, California, without indication of host, in the same 
collection; one broken specimen of undeterminable sex from “quail,” Mount 
Hamilton, California, in the Stanford University collection; one female, with¬ 
out indication of host, from San Diego, California, June, 1921. 
Notes. Speiser (ref. cited) gives a very good re-description of this species 
from the type. It is an easily recognizable form of very peculiar character. 
It is interesting to note that the type of the genus which is the only other 
included species, S. fall if/ons (M alker), also infests gallinaceous birds, Austen 
having reported it from Ortyx virginiana, Geotrygon sylvatica and G. montana, 
among other hosts. 
The colour of the body is evidently to some extent variable, some specimens 
being yellowish brown, others blackish. The setae on the legs and antennae 
are blackish, those on the frons and mesonotum yellowish. The face, clypeus 
and underside of the head are yellowish. There are few setae on the mesonotum 
and these are placed in definite areas as indicated (Fig. 17). 
The antennae in Fig. 17 are pointing downward, their shape is better shown 
in Fig. 18 B. 
The prothoracic spiracles are very large and heavily chitinized. The 
scutellum has a distinctive shape, being very broad and almost emarginate 
posteriorly. On each side of the thorax, just under the vestigial squamae, 
is a remarkable, heavily chitinized, hammer-shaped projection, that is very 
distinctive of the species. 
The abdomen has a dense covering of short setae borne upon small tubercles, 
most of these setae being short and heavy. The basal, chitinized portion of 
the dorsum is large and the remainder is membranous except for a pair of 
plates near the apex. The ventral side is entirely membranous except for a 
pair of plates on the anterior margin of the vulva. 
The ungues (Fig. 18 C) have the outer tooth much longer than the second; 
the few setae on the last tarsal segment are strong, a blunt seta near the base 
of the pulvilli being especially noticeable. 
The wings (Fig. 18 A) are entirely destitute of the microscopic setulae that 
are present in all the other bird-infesting forms known to us. The veins near 
the base and anterior margin of the wing are heavy and black and there is 
a thick anal cross-vein (Cu 2 ). 
