Vol. XXX] ENTM.MoLor.ICAI. NF.YVS 5 



Antennae coarse and with numerous circular sensoria of irregular 

 size. The fourth and fifth segments are about equal in length and are 

 shorter than the third and longer than the sixth. 



Nectaries as in the apterous forms. \Yings long and narrow with 

 median vein having but a single fork. Angle between branches wider 

 and shorter than in Eitlacliiius ri/e\i. 



Mesurements. Length of body a little more than 2 mm. Length of 

 antennal segments not definite because of a deformity in the only 

 available specimen. Ill, 0.56 mm.; IV, 0.34 mm.; V, 0.34 mm.; VI, 

 0.26 mm. Length of hind tibia, 1.33 mm. 



Eulachnus rileyi Williams. (Plate II, E, figs. 1-6.) 



Description made from specimens sent to me by J. J. Davis, 

 and from specimens collected at St. Louis, Missouri ; Chicago, 

 Illinois, and Madison, Wisconsin. 



. Iptcrons viviparous female. General color, orange brown to green- 

 ish black; the color is caused to vary more or less by a grayish pul- 

 verulence covering the body. \Yhen placed in balsam four rows of 

 black spots are visible on the body, and from each one there arises a 

 long spine-like hair. Antennae light at the base and shading to black 

 at the tip. Antennae long and slender and quite spiny. The third 

 segment is not quite as long as four and five together, segments four 

 and six approximately equal. The rostrum is short, not quite reaching 

 the hind coxae. The nectaries are small with a narrow cone-shaped 

 base. Entire body covered with long spine-like hairs. 



Length of body, 2.4 mm. Length of antennal segments, III, 0.45 

 mm.; IV, 0.24 mm.; V. 0.31 mm.; VI, 0.24 mm. Total length, 1.4 mm. 

 Length of hind tibia, 1.6 mm.; hind tarsi, 0.12 mmm. and .22 mm. 



Alatc viviparous female. General color dark green or brown, cov- 

 ered with white waxy powder or threads. When mounted in balsam 

 the head and thorax are brownish and the abdomen greenish brown. 

 Antennae and hind pair of legs black, the tibia of the front pair of legs 

 light colored except at the ends of the segment. Antennae long and 

 slender and set with long black spine-like hairs. The third segment 

 without sensoria, fourth and fifth with one each. Other characters 

 as in apterous form. 



Measurements. Length of body 2 mm. Length of antennal seg- 

 ments, III, 0.44 mm.; IV, 0.25 mm.; V, 0.26 mm.; VI, o.i<> nun. Total 

 length, 1.3 mm. Length of hind tibia, 1.6 mm. Length of hind tarsus, 

 0.12 mm. and .22 mm. 



UNILACHNUS new genus. 



The characters upon which this <jcnus is based are the un- 

 branched median vein and blunt terminal segment \ the n>s 



