October, '09] JOURNAL OP ECONOMIC ENTOMOLOGY 355 



fined to the under surface of the segments, there being only slight 

 indications of the sensoria from above. The numbers of sensoria per 

 segment are about as follows : Joints three, 11 to 13 ; four, five and six, 

 5 to 6 each. Fig. 8. 



Pemphigus corrugatans Sirr. This species seems common and wide- 

 spread, curling the leaves of Crategus and Amelancliier. It was 

 abundant in curled leaves of Crategus macrocapeira and C. crusgalli 

 at Lansing, and leaves of Amelancliier canadensis at Kansas City, 

 Springfield, and AVebster. Alate lice was found in all cases. This 

 is a common species upon Amelancliier alnifolia and Crategus occi- 

 dentalis in the foothills near Fort Collins and upon what I take to be 

 the same plants at Paonia, Colorado. Sensoria : Joints thi'ee, 16 to 20, 

 four, 4 to 6, ; five 2 to 3 ; six, 1. Fig 9. 



Pemphigus ulmifusus Walsh. The galls of this species were shown 

 to me by Dr. Beutenmuller of Palisades, N. J. The leaves of a small 

 elm were much, infested, the larger galls being fully two inches in 

 length. Just an occasional gall was beginning to turn yellow, and 

 in these some alate examples were found. In all the galls stem- 

 mothers were still present; they were very pale yellow in color, large 

 and sub-globular. All of the descendants from the stem-mother were 

 acquiring wings. This gall was abundant on small elms at Washing- 

 ton, but the inmates had escaped. At Woods Hole alate lice wer-j 

 abundant in the galls. 



The alate lice I took were larger than those Thomas described 

 (Eighth 111. Rep. p. 153), averaging 1.60"" in body length and 

 fully 2.20"" to the wing tips, and I find no well marked indication 

 of a fork to the cubital vein. The antenna has joints 3, 4, 5 and 6, all 

 heavih^ ringed, joint 4 being usually the shortest and 5 and 6 sub- 

 equal. The most pronounced peculiarity of the antenna is the ab- 

 sence of a distinct unguis as a differentiated portion of joint 6, resem- 

 bling in this respect, Hamamelistes. Fig. 10. 



Pemphigus tessellata Fitch. This species was taken by Mr. Bragg 

 from the underside of limbs of alder at Webster and Woods Hole. 

 Apterous examples only were seen. 



Pemp>higus populitransversus Riley. Taken on cottonwood leaves 

 at Rochester and at Webster. Very few galls seen. This is a com- 

 mon species infesting eottonwoods in Colorado. Sensoria : Joints 

 three, 3 to 5 ; four, 0-1 ; five and six, 1. Sensoria in distal portion 

 of joints 5 and 6 very large, with 2 to 4 minute hairs in each. Fig. 11. 



Pemphigus populiconduplifolius Cowen. Stem-mothers and young 

 of what seem to be this species were taken in folded leaves of populus 



