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NEMATOCERA. 49 
has undergone for fertilization by insects, and has called forth a great 
deal of attention. The figure below shows the modifications. 
The distribution of the Cecidomyide in space seems to be very 
great ; most regions of the globe furnishing examples of this family. 
They seem to extend into the Arctic Circle, but are more abundant 
as we approach warmer climes. 
Their distribution in time is limited, as far as we know, the 
tertiary ambers alone yielding their remains. From these, two extinct 
genera, Lithomysa and Monodiciana, Lw., have been described. The 
former belongs to the Anaretina, and the latter to the Cecidomyina. 
About twenty-three species in all have been described, amongst the 
sub-genera Zpidosis,* Dirhiza, Diplosis, Cectdomyia, and Asynapta, 
some from America and some from Europe. Jastoptera has also 
been found in a fossil state in Wyoming. Their small size and 
fragile nature would naturally hinder their preservation. 
FIG, 11.—-Avristolochia clematis, showing method of fertilization. 1. Unfertilized 
blossom. 2. Fertilized. A. Funnel. B. The flask with generative 
organs. C. The ovary. 
The classification of the Cecidomyidz is as follows. They can be 
divided, according to Loew, into two sub-families : 
A. Cecidomyina = Cecidomyine, Rd. 
Three or four longitudinal veins on wings, the last two often 
coalescing at the beginning of their course, forming a fork. Ocelli 
absent. 
B. Anaretina = Lestremine, Rd. 
Has a supplementary vein between the second and third of the 
Cecidomyina. ‘This additional vein is furcate. Ocelli are present in 
most of this group.t 
* «*Bernstein-Fauna,” p. 32 Loew, descriptions of C. (Zpidosis) incompleta 
and C. minutissima. 
t+ Cectdogona has no ocelli. 
