No. 413.] ABERRANT PHORIDA FROM TEXAS. 351 
bristly while the ventral side is bare; they show no traces of 
any separate segments and articulations, whereas the halteres 
of Commoptera do. The presence of wings and absence of 
halteres are peculiar to this genus among all Diptera. Wings 
are often absent and rarely both wings and halteres, but in no 
other case are wings present without halteres. In Lvetmoptera 
browni Kellogg (00) the wings are much as in Ecitomyia, but 
the halteres, although somewhat reduced, are distinct. In 
Termitoxenia Wasmann considers the appendages of the thorax 
to be attached to the prothorax, which he believes to be greatly 
enlarged and to cover the dorsum of the entire thorax. This 
would certainly be an unusual development of the prothorax, 
and it seems much more reasonable to suppose that they are 
the halteres, or perhaps possibly reduced wings. It seems 
highly improbable that a dipteron prothorax should have sud- 
denly become so large and have developed wing-like appendages. 
On the other hand, they are quite similar to the halteres of 
Commoptera, and Wasmann’s appendices thoracicales could be 
easily derived from halteres. In Termitoxenia they seem to 
have taken on a new function, at least Wasmann so supposes 
from their peculiar form. He suggests that they may be of 
use as a means of attaching the animal to the body of the 
termite in order to be carried about. 
The abdomen has somewhat larger dorsal plates than Com- 
moptera, but they are nevertheless very much reduced, being 
scarcely visible from the side. The pit and papilla upon the 
anterior part of the fourth dorsal plate are shown in sections 
to be connected with a remarkable gland in the abdomen. The 
dorsal plate of the segment is continued forward to form a 
strongly chitinized ring which passes over into the plate pos- 
teriorly Inside of this ring the integument is very thin and 
delicate, and is folded in to form a pit, surrounded on all sides 
by firm chitin. The bottom of the depression is swollen out 
in the middle to form a papilla, which is evidently to some 
extent eversible, as it shows a different form in almost every 
specimen. It often appears distinctly bifurcate at the tip. The 
tip of the papilla is covered with fine hairs and usually shows 
Some refractive granules, most probably urates of some sort. 
