Tue CRANE-F LIES oF New York — Part I 857 
almost vertical in position. The dorsal part of the postnotum lies between 
the halteres, and the lateral part between the wings and the scutellum 
in front and the halteres and the metapleura behind. This region is 
often erroneously considered as being the metanotum. 
The pleuron of the mesothorax (fig. 126, a) consists of the mesepister- 
num and the mesepimeron. The mesepisternum is the plate making up 
the anterior part of the pleuron. It is bounded caudad by the mesepim- 
eron and ventrad by the mesosternum. Its dorso-cephalic angle is close 
to the mesothoracic spiracle. The mesepimeron is the plate making up the 
posterior part of the pleuron. It is a long sclerite, lymg underneath 
the wing base and bordered behind by the mesonotal postnotum and 
the metepisternum. 
The sternwm of the mesothorax is usually prominent, lying beneath 
the pleura and bearing the middle legs. 
The mesothorax bears the wings of the insect, as well as the middle 
legs. The details of the wing venation are discussed under a separate 
caption (page 860). The wings are always present in crane-flies, but 
they are very tiny and reduced in the genus Chionea, and in many genera 
and species they are so reduced as to be useless for flight. This atrophy 
of the wing may consist of a reduction in width only, the length being 
unaffected and the organ taking on a straplike appearance (as in Tipula 
pribilofensis); or there may be a reduction in both the length and the 
width, the wing in extreme cases (such as T7pula chionoides, Platylimnobia, 
and others) being a mere pad which is shorter than the halteres. As 
a result of the distortion of the wing shape there is a corresponding reduction 
and atrophy of the venation. In the northeastern United States and 
eastern Canada, all the crane-flies are full-winged except the nearly wing- 
less Chionea, mentioned above. 
The wing surface is usually provided with a microscopic pubescence, 
to which are due many of the opalescent reflections in crane-flies (as in 
Antocha, Dicranoptycha, and other genera). In addition to this micro- 
scopic pubescence there is also found, in many scattered groups of genera, 
a strong pubescence, which is apparent with a hand lens. The writer 
regards the retention of this coarse pubescence as being a primitive char- 
acter. Its nature varies. In some genera it covers the whole surface of 
the wing —as in Ormosia, Ula, and Ulomorpha; in many species it is 
confined to certain of the apical cells of the wings—as in Dicranomyia 
