H. F. WILSON 91 



tips, shading to opaque yellow at the base. Legs black except the basal por- 

 tions of the tibiae and tarsi which are yellow. Nectaries and Cauda concolorous 

 with the body. Antennae as long or slightly longer than the body. Antenna! 

 tubercles semi-distinct. Third antennal segment with 1 or 2 large sensoria. 

 Abdomen globose; nectaries as broad as wide and slightly tapering. Cauda 

 short and triangular. Body covered with thick, pointed setae. 



Measurements: Length of body, 1.75 mm.; width, 1 mm. Length of 

 antennal segments: III, 0.51 mm.; IV, 0.38 mm.; V, 0.34 mm.; VI, 0.066 mm.; 

 spur, 0.69 mm. Length of cauda and nectaries cannot be determined in speci- 

 mens at hand. 



Alate viid parous female: General color, head and thorax black with a reddish 

 tinge. Abdomen shining browiiish red. Antennae black at the tip, yellowish 

 at the base. Legs, except base of tibiae and femora, black. Nectaries and 

 Cauda concolorous with the body. Wings with stigma and veins dusky; 

 antennae reaching to the tip of the abdomen and the third segment with as 

 many as 10 large sensoria, although Gillette only gives 4. The number appar- 

 ently varies considerably, since I have found some specimens sent me by Mr. 

 L. C. Bragg with six sensoria. 



Measurements: Length of body, 1.44 mm.; width, 0.84 mm. Length of 

 antennal segments; III, 0.51 mm.; IV, 0.38 mm.; V, 0.35 mm.; VI, 0.135 mm.; 

 spur, 0.67 mm. Length of nectaries ?; length of cauda 0.066 mm.; length of 

 wings, 2.58 mm.; width, 1 mm. 



Microsiphum oregonensis new species? (Plate VI, figs. 17 to 21.) 



Found on Artemesia tridentata at Salisbury, Oregon, July 26, 

 1914. That two species of such similar and unusual characters 

 should exist on the same host in the same locality is more or less 

 open to question, but the present species is questionably described 

 as new on the fact that the setae of the individuals here included 

 are entirely different from those of the preceding species, and 

 while the nectaries are more or less similar there is still a distinct 

 difference. The alate form has not been taken. 



Apterous viviparous female: General color light wine red, with a more 

 or less shining or metalhc appearance. Antennae and legs dusky red except 

 the basal half of the former and the tibiae of the latter. Body globose, 

 oval from above, and sparsely set with long curved specialized setae each of 

 which bears a fiat fan-shaped tip. Antennae as long as the body. Antennal 

 tubercles semi-distinct. Thu-d segment with a single large sensoria near the 

 base. First, second and thu-d segments with spines similar to those on the 

 body. On the third segment these are all on one side. Nectaries twice as 

 long as broad and slightly tapering. Cauda short, broad and blunt. 



Measurements: Length of body, 1.66 mm.; width, 0.88 mm. Length of 

 antennal segments: III, 0.31 mm.; IV, 0.3 mm.; V, 0.27 mm.; VI, 0.11 mm.; 

 spur, 0.49 nun. Length of nectaries, 0.066 mm. ; length of cauda, 0.066 mm. 



TR.VNS. AM. F:NT. SOC. XLI. 



