262 INSECTA. 
FAMILY III. 
TABANIDES. 
- 
Our second family of the Diptera is characterized by a 
salient proboscis, usually terminated by two lips with pro- 
jecting palpi, by the last joint of the antenne being annu- 
lated, and by a sucker composed of six pieces: it comprises 
the genus 
Tasanus, Lin.(1) 
These Diptera are very similar to large Flies, and well known by 
the torment they occasion to cattle, by piercing their skin in order 
to suck their blood. ‘Their body is usually but slightly pilose. 
Their head is as wide as the thorax, almost hemispherical, and with 
the exception of a small space, particularly in the males, occupied 
by two eyes, generally of a golden-green, with purple spots or streaks. 
Their antennz are about the length of the head, and are composed 
of three joints, the last of which is the longest, terminates in a 
point, has neither seta nor stilet at the end, is frequently lunate above 
its base, and with from three to seven transverse and superficial divi- 
sions. The proboscis of the greater number is almost membranous, 
perpendicular, of the length of the head or somewhat shorter, 
almost cylindrical, and terminated by two elongated lips. The two 
palpi, usually incumbent on it, are thick, pilose, conical, compressed 
and biarticulated. The sucker inclosed in the proboscis is composed 
of six small pieces, in the form of lancets, which, by their number — 
and relative situation, correspond to the parts of the mouth in the 
(1) This family is not connected with the preceding one. It appears to me to 
form a particular series with the following, leading from the Nemocerz to the 
Atericere. The preceding family would form another which would also lead to 
them, so that the last of this one would be approximated to the last of the Nota- 
canthi. The Culicides and Tabanides are the only Diptera whose sucker is com- 
posed of six pieces. 
