778 CHARLES PAauL ALEXANDER 
DISTRIBUTION 
GEOLOGICAL DISTRIBUTION 
The source of origin of the crane-flies is still largely problematical, 
but the preponderance of evidence now seems to indicate that they came 
from some neuropteroid ancestor far back in Mesozoic times. This is 
expressed by Needham (1908:221) as follows: ‘‘The suggestion has 
been made before by others, and I think it very possible, that some 
Panorpidlike neuropteroid mutant got its center of gravity hitched for- 
ward, its hind wings reduced, and started the dipterous line of evolution.” 
The first insects that can be definitely referred to the Tipulidae appeared 
rather suddenly in late Mesozoic times. They belong almost entirely 
to the subfamily Tipulinae, but the records are very scanty and for the 
most part unsatisfactory. The evidence that specimens of Tanyderidae, 
Ptychopteridae, or Limnobiinae occurred at that time is very doubtful. 
In the Tertiaries, however, the group was extraordinarily developed and 
it seems quite possible that the family reached its maximum of diversity 
in the Miocene period or a little later and is now a waning group. From 
the Oligocene period of British Columbia, Handlirsch (1910) has recorded 
a curious tanyderid under the name Etoptychoptera. _The Florissant 
beds of Colorado were laid down in a lake that is supposed to be of the 
late Oligocene or the early Miocene age. There have been taken from 
these beds hundreds if not thousands of specimens, representing about 
seventy-five species, indicating the extreme richness of the crane-fly 
fauna during that age. On one slab of the deposit Scudder found a 
specimen of his Dicranomyia inferna which was partly overlain by a 
specimen of his D. fontainez, a condition very suggestive of the remarkable 
richness of this fauna. The abundance of species in the amber fauna, 
likewise of the Tertiaries, was indicated by Loew in 1850 and more recently 
elaborated by Meunier. The present knowledge of the Florissant fauna 
is due to the work of Scudder, Cockerell, and Wickham. 
GEOGRAPHICAL DISTRIBUTION 
A summary of the crane-fly fauna of the world 
The four families comprising the crane-flies are represented in almost 
every part of the world where life is possible. Apparently the range 
of the group is restricted only by great extremes of temperature. 
