_ TABANIDZ OF ,OHIO,.. . ie 
Many species of Tabanus have the wings entirely. transpar- 
ent while. others have dark areas which furnish distinctive char- 
acters. In T. sulcifrons dark markings are located at the bifur- 
cation of. the third vein and’ along the veins at the discal end of 
the discal cell; when markings are present on the wings of the 
various species of ‘Tabanus it is more common to find them where 
the third vein branches and along the veirs or parts of veins 
which are most. nearly transverse. Exceptions to this. may be 
seen by reference to venustus and turbidus. 
Abdomen. The markings of the abdomen in this’ species. 
consist of rather broad white. triangles and white posterior mar- 
gins on most of the segments. These markings are formed by 
the color and arrangement of the vestiture, which consists of 
hairs and dust or pollen. With a bristle brush the hair may be 
easily removed from a dry specimen, but on the same kind of 
a specimen the pollen is more persistent and therefore more read- 
ily removed by rubbing after it has been moistened. 
When all the vestiture has been removed the abdomen is 
nearly a uniform brown all over and appears quite different than 
in a perfect specimen. 
Seven segments are visible to the unaided eye. The circum- 
ference decreases from the second backward, and concealed by 
the seventh or smallest are what may be considered as three very 
much reduced additional segments, which are easily removed by 
the aid of a needle and which can only be differentiated satisfac- 
torily by the use of a microscope or strong lense. These segments 
besides being smaller are much modified in both sexes. In the 
female from ventral view, is visible a sclerite, infraanal plate, 
which is interesting from a specific standpoint, and its form may 
be seen best by reference to Fig. 9, q. plate I. 
The claspers of the male are borne by the eighth segment, 
each of these are composed of two joints, which are movable : 
therefore they appear different in different specimens as may be 
4cen by reference to the figures, plate I, Figs. 6 and to. 
MALES COMPARED. WITH FEMALES. 
The males and females in the entire family are easily dis- 
distinguished from the fact that the former sex has the eyes con- 
tiguous and the latter has the eyes plainly separated. In all the 
species studied the male has the proboscis longer and slenderer, 
and the front feet larger than in the female. The palpi in the 
female point downward and the second segment is carried in 
front of the proboscis, while in the male they often turn upward 
and the second segment is carried against the face. 
Usually the males and females of the same species are easily 
associated, but in a number of species it is not an easy matter at 
least until they have been taken in the same locality in the field. 
