THE CANADIAN ENTOMOLOGIST 



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excepting tibiae, which are pale at extremities. Wings as in 

 illustration, the media usually one-branched, although this char- 

 acter is variable, Mr. Monell has collected specimens of this species 

 in St. Louis which had the media unbranched, and he also collected 

 one individual with a bifurcate media. Regarding this variable 

 venation Mr. Monell wrote Dr. H. Schouteden, who replied under 

 date of April 23, 1905, as follows: "A Lachnus with cubital vein 

 unforked is quite unknown to me, but there are some species with 

 only one fork (L. agilis)" Cornicles and cauda as in wingless 

 form. 



Average measurements from 3 specimens in balsam as follows- 

 Length of body 2 mm., width 0.50 mm.; length of wing 2.2 mm., 

 width 0.70 mm.; length of middle tibia 0.79 mm., of hind tibia 

 1.62 mm.; length of first tarsal segment 0.113 mm., of second tarsal 

 segment 0.209 mm. 



Antennal measurements as follows: 



Winged Male. 

 (PI. VII, fig. 47). 



Head and thorax black; abdomen pale brownish, with a dull 

 orange tint, and the entire body covered with a white pulverulence. 

 Antennae black, reaching nearly to tip of body; segment III longest; 

 segment III with 60 to 84 faintly tuberculate, circular sensoria, 

 IV with 22 to 41, V with 10 to 29, not including the usual large 

 distal sensorium, and segment VI with 3 to 5, not including the 

 usual large sensorium. Eyes black. Wings as in the viviparous 

 female. Legs black, excepting the pale extreme bases of femora 

 and the brownish basal halves of tibiae. Cornicles and cauda as 

 in other forms, the anal plate dusky. 



Average measurements from six individuals in balsam as 

 follows: Length of body 1.59 mm., width 0.47 mm.; length of wing 

 2.61 mm., width 0.83 mm. Antennal measurements as follows: 



