196 Hippoboscidae (Diptera Pupipara) 
the aedeagus as there is a chitinized piece at the base, evidently the apodeme 
of the penis. 
The hind tibiae suggest those of Pseudolfersia spinifera, described below, 
but the small tubercles are in a single row and the circular structures near them 
are slightly different in appearance. The posterior tarsi are toothed on the 
margins, but not so strongly as in P. spinifera and the teeth do not extend to 
the apex of the last segment. The outer tooth of the claws is very slender, 
the middle tooth distinctly wider and with a blunt, rounded tip. The arrange¬ 
ment of the fine setulae on the wing membranes is like that figured for 
P. spinifera, but there are not so many in the basal part of the wing and none 
at all in the anal region. 
Our interpretation of the wing venation (Fig. 12) is in accord with the 
Comstock-Needham system of nomenclature. Massonat (1909) who has 
attempted to apply this system seems not entirely to have understood it and 
has arrived at results which are impossible under its application. His R 3 is 
in reality R 4+5 , his R 2 is R 2+ 3 . 
Genus Pseudolfersia Coquillet. 
Pseudolfersia spinifera (Leach). 
Figs. 13, 14. 
1818. Feronia spinifera Leach, Mem. Wernerian Nat. Hist. Soc. n. 557; PI. 26, figs. 1-3. 
1901. Pseudolfersia diomedeae Coquillet, Proc. Washington Acad. Sci. in. 379. 
1902. Pseudolfersia spinifera (Leach), Speiser, Zeitschr. f. syst. Hym. und Dipt. n. 146-149. 
1903. Olfersia vulturis Van der Wulp, Biologia Centrali Americana, Diptera, n. 429; PI. 13, 
figs. 1-1 a. 
1903. Pseudolfersia vulturis (Van der Wulp), Austen, Ann. Mag. Nat. Hist. (7), xn. 261. 
1903. Pseudolfersia spinifera (Leach), Austen, Ibid. p. 265. 
Previous Records. A tropicopolitan species occurring on a wide range 
of hosts including especially sea birds. Austen (ref. cited) gives a list of the 
species from which it has been taken and also a list of the names that have 
been applied to it. 
Specimens Examined. A paratype male of Pseudolfersia diomedeae Coq., 
from Diomedea irrorata, Galapagos Ids.; a single male from Fregata aquila, 
Cape San Lucas, Lower California; three males from “king vulture,” Belize, 
British Honduras. All of these specimens from the Stanford University 
collection. 
Notes. We are entirely convinced that the specimens that we have 
examined represent but a single species— P. spinifera (Leach). Major Austen 
has kindly compared one of our specimens from “king vulture” with the type 
of vulturis in the British Museum and has identified it as this species. Our 
specimen from frigate bird agrees exactly with the very good description of 
spinifera given by Speiser and as this species is known to occur characteristically 
on the frigate bird, we do not doubt the correctness of our determination. 
The distribution of the species is remarkable, but it should be borne in mind 
