1942] 
Notes on Hippoboscidce 
109 
with only the basal and sometimes a pair of preapical dorsal 
sclerites differentiated; otherwise membranous and uniformly 
hairy above and below; no median striated area dorsally. Pilos- 
ity of body and legs very long and dense, the whole insect 
hirsute. 
Brachypteromyia is closely related to Myophthiria Rondani, 
with which genus Ferris (1928, Pan-Pacific Entom., IV, p. 140) 
proposes to unite it. No serious objection to such a course can 
be offered. The discovery of a second species, much more like 
B. fimbriata than like the two or three known species of 
Myophthiria , suggests, however, that Brachypteromyia might 
be retained at least with subgeneric rank. Three main differ- 
ences can be pointed out between the two groups. In Myoph- 
thiria the thorax is slightly less evolved, with the dorsal sutures 
more distinct, the scutellum longer and narrower, and the 
chaetotaxy sparser and more in accordance with the primitive 
arrangement. The wing is longer and narrower, with the vena- 
tion more distinct and somewhat less reduced. The abdomen is 
much less hirsute; in the female it bears dorsally a pair of 
transverse preapical sclerotized plates, preceded by one or two 
small median sclerites; while in the male there are, in addition 
to the preapical pair, three transverse median tergal plates, the 
hindmost of which is very large. 
The three females of B. fimbriata examined show dorsally no 
traces of median sclerites nor of sclerotized preapical plates. 
In two males of that species there appear to be two minute 
preapical sclerites, placed far apart; but I can find no trace of 
them in the male holotype of B. neotropica. More material will 
have to be studied before a final conclusion can be reached. If, 
however, the difference in the structure of the abdomen proves 
reliable, there might be some justification for retaining Bra- 
chypteromyia as generically distinct from Myophthiria. 
It should also be noted that Brachypteromyia is the most 
specialized type of the subfamily Ornithomyinse. It is the final 
step in a series of changes leading from the fully winged to the 
subapterous condition. This series, one of the most instructive 
evolutionary sequences I am acquainted with, is perhaps best 
understood by following first the gradual reduction of the 
wings. The more common species of Ornithomyia , such as the 
Palearctic O. avicularia (Linne) and the Holarctic O. fringil- 
lina Curtis (= O. anchineuria Speiser), have fully developed 
