DIPTERA. 
623 
Hemerodromia, Holfm., has the two fore coxae very long-. 
Sicus, Latr. {Tachydromia, Meig-.)> has the first or second pair of thighs thickened. 
Drapetis, Meig., has the last joint of the antennae subglobose, and the proboscis scarcely exserted. 
M. Macquart [as well as Mr. Haliday and Professor Zetterstedt] have established several additional genera, 
which it would occupy too much space to notice in detail. 
The other Tanystoma of our first division have the body generally short, broad, with the head 
exactly applied to the thorax ; the wings extended, and the abdomen triangular. They have, in a 
word, the appearance of Domestic Flies. The proboscis is often very long. 
Cyrtus, Latr. [yesiculosa, Latr.], — 
Intermediate between Empis and Bombylius, with the wings deflexed at each side of the body ; the 
alulets very large, and covering the balancers ; the head small and globular ; the thorax very gibbose ; 
the abdomen vesiculose, and the proboscis directed backwards, or wanting. 
Some have a proboscis directed backwards. 
Panops, Lam., with antennee longer than the head, cylindric, and 3-jointed, without a terminal seta. 
Cyrtus proper, with antennae very small, 2-jointed, with a seta at the tip. 
The others have not an extraordinary proboscis. 
Astomella, Duf,, has the antennae 3-jointed, with the last joint forming a compressed, elongated knob, without 
a seta. 
Henops, Illig. {Ogcodes, Latr.), has antennae inserted before the eyes, small, and 2-jointed, with a terminal seta. 
Acrocera, Meig., differs in having the antennae inserted behind the eyes. 
Bombylius, Linn. (Bombyliers, Latr.),— 
Has the wings extended horizontally on each side of the body, with the balancers naked ; the thorax 
higher than the head, or gibbose, as in Cyrtus ; the antennae close together, and the abdomen trian- 
gular, or conical. The proboscis is porrected in front, and very long in many species. The antennae 
are always 3-jointed, the last being elongated, compressed, fusiform, generally terminated by a very 
short style, and never by an elongated seta. The palpi are slender, filiform ; the legs are long and 
slender. These insects fly wfith wonderful rapidity, hovering over flowers without settling, and intro- 
ducing their long proboscis in order to suck up the honey, and making a sharp buzzing noise. I suppose 
that their larvae, like those of Anthrax, are parasites. 
Some have the proboscis evidently longer than the head, very slender, and pointed at the tip. 
ToxopTiora, Meig., has the antennae as long as the head and thorax, filiform, pointed at the tip, and the body 
elongated. 
Xestomyza, Wied., has shorter antennae, but the first joint is elongated, and longer than the other joints, and 
fusiform, as is also the third. 
Apatomyza, Wied., has the first joint also very long, but cylindrical. In the subsequent subgenera the last 
joint [of the antennae] is the longest, and sometimes the two basal joints of the antennae are short, and of nearly 
equal length. 
Lasius, Wied., has the head nearly occupied in one sex by the eyes, and the last joint of the antennae very long, 
nearly linear, compressed, and without a terminal style ; the abdomen is voluminous ; the proboscis occa- 
sionally extends beneath and beyond the extremity of the body, which seems to connect this genus with [Cyrtus 
or] the tribe of Vesiculoscs. 
Usia, Latr., has the last joint of the antennae ovoid, conic, obtuse, or truncated at the tip, and terminated by a 
style ; the palpi not apparent. [South of Europe, or Africa.] 
Phthiria, Meig., resembles Usia in the antennae, but with distinct palpi ; sometimes the second joint is evidently 
shorter than the first ; the last is long, generally almost cylindric, and pointed at the tip. 
Bombylius proper, has very distinct palpi, and the body is clothed with a thick woolly coating of hairs. B. major, 
Linn., a very abundant species [in this country]. 
Geron, Meig., has the last joint of the antennae longer, terminating like an awl, and the wings wanting one of 
the transverse nerves near the hind margin. 
Thlipsomyza, Wied., is allied to the preceding, and Phthiria ; and I presume that 
Amictus, Wied., also approaches them. Both have the basal joint of the antennae longer than the second, and 
cylindrical ; the wings of Amictus, however, differ from the preceding subgenera. 
The other species have the proboscis not longer than the head, and thickened at the tip, and the basal joint of 
the antennae is the largest. 
Ploas, Latr. (ConopJiorus, Meig.), has this joint much thicker than the rest. 
Cyllenia, has this joint merely longer, but not thicker, and the abdomen is more elongated, and nearly conical. 
Anthrax, Scop. {Anthracii, Latr.), — 
Similar to the Bombylii, with the body depressed, or but slightly elevated above ; not gibbose, with 
the head as high and broad as the thor.ax. The antennae are always very short, and, except in 
