860 CHARLES PauL ALEXANDER 
are of great importance in classification. These spurs are lacking in the 
tribes Limnobiini, Antochini, and Eriopterini, but are present in the 
remainder of the Tipulidae tho in some cases they are so small as to 
require a low-powered microscope for their detection. 
The tarsal segments.— The tarsus, or foot of the fly, is made up of the 
terminal five segments. The first of these segments is the longest and 
is called the metatarsus. The remaining segments gradually decrease 
in length to the last, which bears the claws, or wngues, and, when it is 
present, the empodium between the claws. In Bittacomorpha the 
metatarsus is swollen and bladder-like. In one species of Lecteria the 
metatarsus bears a group of three stout spines at the extreme base. 
The claws of most crane-flies are quite smooth (fig. 127, c, Rhabdo- 
mastix), but those of species of the tribe Limnobiini have teeth on the 
ventral side (fig. 127, a, Limnobia; fig. 127, 3, Dicranomyia). <A sim- 
ilar condition is found in certain Dolichopezini, such as Brachypremna 
and Tanypremna, but not in Megistocera. 
The transverse suture 
The transverse suture is considered one of the important characters 
for use in distinguishing the Tipulidae from related families of flies, such 
as the Dixidae, the Mycetophilidae, and others. It is in the shape of 
a low VY, and separates the mesonotal prescutum from the scutum. 
The wings and their venation 
The wings of crane-flies, with their remarkably constant venation and 
pattern, furnish the easiest and best characters for recognition of the 
various forms. In the great majority of cases a glance at the wing is 
sufficient for the determination of the species, and it is for this reason 
that considerable emphasis is here placed on these organs. This paper 
discusses only in a rather elementary way the essentials of the wing 
venation, but Needham (1908) has made a critical survey of the character 
in all the genera of the Tipulidae known at the time his work was pre- 
pared, and his paper is absolutely essential to the student of this group 
of insects. 
The wing is made up of a series of longitudinal veins running 
from the base to the outer margin and bound together at various points 
by cross-veins and by deflections of the longitudinal veins which produce 
