Miller — Pond lAllies of Northeastern United States. 13 



tauqua Lake, N. Y., the number ranges from 9 to 16, but in 80 

 percent lies between 10 and 13 (inclusive) with a well marked 

 maximum (36.1 percent) on 12. 



I have referred to these plants as types rather than species 

 because there is every reason to believe that each is an aggre- 

 gate of several well defined forms. The erect, subterete-pe- 

 tioled plant is the true Nymphma advena of Alton* (type local- 

 ity probably Philadelphia, Pa.). The floating, flat-petioled 

 forms may for the present stand as Nymphoea variegata (Engel- 

 mann).f 



*[Nyinpha\ advenaa Alton, Hortus Kewensis, II, p. 226, 1789. 

 ^{NupJiar advena] var. variegatiim Engelmann m Gray, Man. Bot. 

 Northern U. S., 5th ed. p. 57, 1867. Type probably from Michigan. 



EXPLANATION OF PLATE. 



Upper figure, Nymphma variegata (Engelmann). Photographed at 

 Lake Titus, near Malone, Franklin County, New York, by E. W. 

 Nelson. 



Lower figure, Nymphma advena Alton. Photographed at Monteur's 

 Pond, Knox County, Indiana, by Robert Rldgway. The head of a man 

 standing among the Illy leaves may be distinguished near centre of this 

 picture. 



