238 MAINE AGRICULTURAL EXPERIMENT STATION. I9IO. 



americana. The differences in venation cited by Riley will not 

 hold for Maine material, as M has so far been found to be 

 obsolete at base in both rileyi and americana. Moreover Pro- 

 fessor Oestlvmd records an occasional complete M for americana 

 (1887). However, absolutely no biological evidence has been 

 recorded which would serve to link rileyi and americana and 

 they should undoubtedly be held separate until careful experi- 

 mental rearing evidence has definitely settled this point. If 

 americana ■ should prove to be a synonym of rileyi and rileyi 

 should prove to be a synonym of iilmi of Europe, we should 

 have a curious reversion of ulmi Riley of America to ulmi Linn, 

 of Europe. 



Bibliography. 

 1868. (1869). Eriosoma ulmi Riley; Rept. Ins. Mo. i: 123, 124. Ac- 

 count of work and original description of winged 

 forms and young lice. Remedies. 

 1876-1879. Schisoneura rileyi Thomas. Trans. 111. Hort. Soc. 1876, 



p. 191 ; id. Rept. Ent. III. 8 : 136, 137, 1879, nom. nov. 

 for Eriosoma ulmi Riley. Systematic discussion and 

 description of work. Description of insect quoted 

 from Riley. 

 1885. Schisoneura rileyi, Forbes. Rept. Ent. 111. 14 : 1 14. 



1887. Schisoneura rileyi, Oestlund. Aphid. Minn. p. 27. Description 



of winged form and pseudo gall. 



1888. Schisoneura rileyi, Lintner. 3rd Report, p. 125. 



1890. Schisoneura rileyi, Packard. Fifth Rept. U. S. Entom. Com. 



Wash. Original description of insect quoted. 

 1897. Schisoneura rileyi, Lintner. 13th Report, p. 374. Mere mention. 

 1901. Schisoneura rileyi, Hunter. Aphid of N. A., p. 84. Bibliography 



in part. 

 1905. Schisoneura rileyi. Felt, N. Y. St. Mus. Memoir 8: pp. 172, 192. 



Brief description of work and remedies. 

 1909. Schisoneura rileyi, Gillette. Journal Ec. Ent. Oct. Suggests that 

 it may be same species as Schisoneura ulmi {americana) . 

 Explanation of Plates. 

 Fig. 126. fetraneura (colophoidea) graminis. Gall collected from 

 Ulmus americana. Orono, Maine. July 8, 1909. 



Fig. 127. Tetraneura ulmisacculi. Galls collected from Ulmus montana 

 var. Camperdown pendula. Orono, Maine, July 6, 1909. 



Fig. 128. "Schisoneura americana : c, c, leaf showing curl — nat. size : 

 a, winter egg; b, stem-mother; d, winged female; i, her antennae; j, her 

 tarsus ; e, true female, ventral view showing solitary egg ; g, her tarsus 

 from beneath; f, anus and genital points of male; h, antennae of 4th 

 generation — ail enlarged." After Riley. 



Fig. 129. Colopha ulmicola : a, leaf showing galls from above and 

 beneath — nat. size; b, impregnated egg surrounded by skin of true fe- 

 male ; c, newly born young of 2d generation, ventral view ; h, its an- 



