242 ENTOMOLOGICAL NEWS. 



In order to account for the apparent discrepancy the writer 

 undertook an investigation of the ovipositors of such forms 

 as he could find about Ithaca, New York, viz., N. undnlata, 

 N. z'ariabilis, N. insulata and A : . irrorata. 



It was apparent at once that the first three possess struc- 

 tures ill adapted to making incisions in plant tissues of suffi- 

 cient size to receive the eggs. The last species, however, pos- 

 sesses an ovipositor capable of performing such a function. 

 (Compare Plate XIV, Figs, i and 5, and Plate XV, Figs. 9 

 and 5.) Upon the basis of this preliminary examination it 

 was asserted that N' irrorata would be found to place its eggs 

 in the tissue of plants. 



Nothing more was done about the matter until spring, when 

 N. irrorata females were observed to place their eggs in the 

 stems of moneywort (Lysimachia nummula-ria L.), luncus, 







and dead Typha stems.* Here then was a member of the 

 genus Notonccta in America that agreed with Regimbart's 

 notes on TV. ghiuca, and the writer became interested in a 

 little study of the form and function correlated with the activ- 

 ity under discussion. 



N. ylanca was secured for study through the kindness of 

 Edmund Gibson, of the National Museum. One female, a 

 pinned specimen, was relaxed sufficiently to permit the re- 

 moval of the drilling parts. An examination of these parts 

 disclosed the fact that they resemble those of our N. irrorata 

 rather than those possessed by the rest of the American series 

 examined. (See Plate XV, Fig. 6.) 



Sufficient material of TV. irrorata, N. undulata a'.id TV z'ari- 

 abilis was examined to establish the fact that there exists for 

 these forms at least some constancy of size and form. An 

 examination of the accompanying Plate XV will suffice to in- 

 dicate that, although all are equipped to abrade the surface 

 of the stems, only TV. irrorata** of our American forms pos- 

 sesses an ovipositor comparable to that of the European 

 glanca. 



* See Hungerford. Ento. News XXYIIT. p. 271, foot note. 

 ** The palaearctic .V. lutra, reported for this country, also possesses 

 this sort of a structure. (See Plate XV, Fig. i.) 



