24 



PAPERS ON APHIDID^. 



more or l(»ss in the nunibcr of hairs borne, on each, sonu^ having tAVO 

 and others but one. The ccplialio and thoracic hairs arc unknobbod 

 or but inconspicuously capitate, and those on the abdomen may also 

 be capitate or not, usually inconspicuously knobbed. 



Eyes dark red to blackish. Antennae dusky to black, reaching a 

 little beyond tip of abdomen; relative lengths of segments as in the 

 other forms; segment III with 13 to 16 oval sensoria more or less in 

 a row; IV with 3 to 5; V with 3 to 5, not including the usual distal 

 one; and VI base with 1 sensorium surrounded by several smaller 

 ones at the tip (fig. 13. a). Beak not reaching coxa^ of second pair of 

 legs. Venation as described for the female. Cornitdes and cauda 

 dusky, the latter edged with black; in form they agree with those of 

 the viviparous generations. 



Fifi. 13.— The yellow clover aphis: Winged male, much enlarged, a, Antenna of same greatly enlarged. 



(Original.) 



Measurements (averages): Length of body, 1.3 mm.; width, 0.53 

 mm.; expanse of wings, 4.1 mm.; length of wing, 1.8 mm.; cornicles, 

 0.049 mm.; hind tarsus, 0.130 mm. Antennal measurements as 

 follows : 



' .Measurements made immediately upon mounting in balsam; other antennal measurements are from 

 balsam mounts after standing and clearing. 



