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EQUISETACES. 
(HoRSETAIL FaMILy.) 
Equisetum arvense, Z. (ComMMoN HorsETAIL.) 
Moist places. Very common. On the railroad beds, a prostrate, 
much branched form occurs, caused by the continualpassing of 
trains, which prevents the plant attaining its ordinary height. 
Equisetum sylvaticum, L. 
In shady places. Frequent. A very graceful plant. 
Equisetum limosum, ZL. 
Open wet places. Frequent. 
Equisetum hyemale, Z. (Scourine Rusu.) 
Near Cold Spring, Salem (Dr. G. A. Perkins); Methuen, on the 
bed of the M. & L. R. R.; Danvers, on the bed of the Newburyport 
R. R.; ‘‘moist woods, Lynn” (Bigelow’s Fl. Bost., 1814). The 
_least common species. 
FILICES. 
(FERNS. ) 
Notr.—This order and the Ophioglossacee have been rearranged to 
conform to the ‘‘Systematic Fern List,” but very recently (Gct., 1880) 
published by Professor Daniel C. Eaton of New Haven. 
Polypodium vulgare, Z. (PoLypopy.) 
Covering shaded rocks. Common. 
Var. Cambricum (English authors). 
A specimen corresponding to this variety was found some years 
since, at Andover, by Mr. Jackson T. Dawson. 
Adiantum pedatum, Z. (MaIpDENHAIR.) 
Towns of the Merrimac valley, frequent; and in small stations 
elsewhere. 
Pteris aquilina, Z. (CoMMON BRAKE.) 
In half shade on well drained soil. Quite common. A variety hav- 
ing the fronds several times pinnate, but not ternate, is occasionally 
met with; the same form is found near Boston (E. H. Hitchings). 
Woodwardia Virginica, Smith. (VirGrntan CHAIN-FERN.) 
Borders of ponds, extending its rhizomes under the water; swamps, 
etc. Frequent. 
Woodwardia angustifolia, Smith. (NARROW-LEAVED CHAIN- 
FERN.) 
Magnolia swamp, Gloucester (J. H. S. and J. R.); ‘‘ Essex county” 
(memo. Dr. Chas. Pickering). Rare. 
