1922} 



PFEIFFER — MONOGRAPH OF THE ISOETACEAE 1CT 



N. Y. Bot. Gard. Herb.); Mystic Pond, mouth of Arling- 

 ton Brook, 2 June, 18G7, Boott (Mo. Bot. Gard. Herb.); 

 along banks of Mystic Pond, 21 October, 1866, Boott (Mo. 

 Bot. Gard. Herb.) ; Mystic Pond, 14 and 30 July, 1864, Boott 

 (Gray Herb.) ; east side of Mystic Pond, 8 September, 1867. 

 Boott (Mo. Bot. Gard. Herb.) ; west side of Mystic Pond, 

 north of Brook, 12 July, 1808, Boott (Gray Herb.) ; south 

 side of Spy Pond, Arlington, 5 and 9 September, 1 857, Boott 

 (Mo. Bot. Gard. Herb.); Spot Pond, G September, 1868, 

 Boott (N. Y. Bot. Gard. Herb.); Spot Pond, Stoneham, 23 

 July, 18G7, Boott (Mo. Bot. Gard. Herb.); Spot Pond, 18 

 November, 18GG, Boott (U. S. Nat. Herb.) ; Horn Pond, Wo- 

 burn, September, 18G2, Mann (Gray Herb.) ; island in middle 

 of Horn Pond, 11 July, 18G7, Boott (Mo. Bot. Gard. 

 Herb, and Gray Herb.) ; northwest side Horn Pond, 1G Sep- 

 tember, 1869, Boott (N. Y. Bot. Gard. Herb.) ; Fresh Pond, 

 17 September, 18G7, Boott (Mo. Bot. Gard. Herb, and Gray 



Herb. ) : Concord Brook 



(Mo. Bot. 



Gard. Herb.); Round Pond, Woburn, 1 October, 1874, 

 Davenport (N. Y. Bot. Gard. Herb.); Hammond's Pond, 

 Brookline, without date, C. E. Faxon (Mo. Bot. Gard. 

 Herb.); Round Pond, Woburn, without date, C. E. Faxon 

 (Mo. Bot. Gard. Herb.); Hammond's Pond, 1878, Farlow 

 (Mo. Bot. Gard. Herb.) ; Tofit Swamp Brook, Lexington, 17 

 July, 18G7, Boott (Gray Herb, and N. Y. Bot. Gard. Herb.) ; 

 brook in Tofit Swamp, Lexington, !) September, 18G7, Boott 

 (Mo. Bot. Gard. Herb, and Gray Herb.); South Natick, 14 

 July, 1879, Morong (Mo. Bot. Gard. Herb.); "entirely sub- 

 merged in pool, South Natick", 18 August, 1883, Morong 

 (N. Y. Bot. Gard. Herb.); ponds, West Cambridge; 1861, 

 Boott (Mo. Bot. Gard. Herb.) ; Concord, in streams, Sep- 

 tember, 1863, Mann (Gray Herb.); Concord, 1 October, 

 18G3, Mann (Mo. Bot. Gard. Herb.) ; Concord, without date, 

 Mann (Gray Herb.) ; small pond in Winchester (for- 

 merly Woburn), August, 1876, Morong 858 (U. S. Nat. 

 Herb.) ; small pond in Winchester, 22 August, 187G, Morong 

 (N. Y. Bot. Gard. Herb.) ; brooks, slow moving water, Mel- 

 rose, 8 July, 1875, Morong (N. Y. Bot. Gard. Herb.) ; in 

 running water, Melrose, September, 1876, Morong (U. S. 

 Nat. Herb.); Sandbury River, Framingham, September, 



