OF WASHINGTON. 1 75 



One specimen, Ft. Collins, Colo. 



Closely related to Ch. ptinciinervis, but larger and differently 

 marked ; quite noticeable by the band on hind femora. 



Leucochrysa americana, n. sp. 



Pale greenish. A transverse reddish spot under each antenna ; above is 

 a transverse red line bent downward in the middle, and giving off a spur 

 between the antennae. Vertex with two deep depressions. Antennae 

 wholly pale, longer than wings, basal joint short and stout. Prothorax 

 short, narrowed in front; with a short black spot in the middle of the 

 front margin, and a reddish-brown line on each anterior side. Legs pale. 

 Abdomen pale, with a large reddish spot on the last ventral segment, and 

 a dot on each side on the genitalia. Wings hyaline, rounded at tips; the 

 hind pair narrowed and more acute; the pterostigma brownish, distinct. 

 The third cubital cell much longer than the second, not very much 

 broader; the divisorj veinlet arising from quite near to the postcubitus. 

 The sector of the radius is very mUch nearer to the radius at pterostigma 

 than in the middle of its length. Alar expanse 27 mm. 



One specimen, Auburn, Ala. 



Easily separated from L. floridana by its smaller size and 

 different markings. 



In discussion Mr. Schwarz referred to the fact that we badly 

 need synoptic tables of the lace-winged flies the published 

 descriptions are so widely scattered. Mr. Banks spoke of the 

 characters used in classification and showed that for specific 

 separation the characters are almost entirely colorational. Few 

 or no structural characters of specific value can be found. 



Mr. Ashmead stated that he had studied these insects to some 

 extent and believed that if carefully studied venation would show 

 characters of value. 



Mr. Banks expressed himself as of the opinion that the 

 venational characters are absolutely worthless. He showed that 

 the two fore- wings of the same individual may differ in venation. 

 Mr. Ashmead stated that the same difficulty exists with the 

 dragon flies and with the Orthoptera, but that with prolonged 

 study, even with this difficulty, Saussure has ascertained many 

 excellent venational characters with the Orthoptera. 



Mr. Marlatt said that a complicated venation should always be 

 approached with caution and that in his opinion venation varies 

 within specific limits in direct ratio to its complication. He 



