198 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



marginale, var. elegans J. Robinson, Ferns of Essex County, Mass., 

 151, 1875.) 



Rich woods; frequent. 



T. noveboracensis (L.) Nieuwl. New York Shield Fern. — 

 Moist well-drained woods; common. 



T. palustris Schott. Marsh Fern.— {D. Thelypteris 111. Fl. ed. 

 2; A. Thelypteris MsLXi. ed. 7.) 



Wet meadows, swampy thickets and moist woodland; common. 

 On the summit of Greylock, 3500 feet. 



T. Phegopteris (L.) Slosson. Beech Fern. — Cool woods, espe- 

 cially on moist banks; frequent in the valley, common on the plateau. 



T. simulata (Davenp.) Nieuwl. — Swampy woods, in small col- 

 onies; occasional. Washington (C. S. Lewis); Ward Pond, Becket; 

 Shaw Pond, Otis; Big Pond, Otis; Sandisfield (Walters). 



T. spinulosa (O. F. Miiller) Nieuwl. Spinulose Shield Fern. — 

 Swampy woods ; frequent. 



var. americana (Fisch.) Weatherby. — (var. dilatatum, f. anaden- 

 ium Man. ed. 7; D. dilatata 111. Fl. ed. 2.) 



Common in rocky woods on the upper slopes of Greylock, and prob- 

 ably occasional on the plateau, as a specimen collected by C. S. Lewis 

 from a shady swamp in Washington (altitude 1700 feet) has been 

 identified by C. A. Weatherby as this variety. 



var. intermedia (Muhl.) Nieuwl. — (Z). intermedia 111. Fl. ed. 2.) 



Rocky or swampy woods; common. Broad forms approaching 

 var. americana occur in cool woods and swamps, as at Ice Glen, 

 Stockbridge; Ice Gorge, Great Barrington; The Dome, Mt. Washing- 

 ton. A form with very narrow pinnules, approaching var. concor- 

 diana occurs on Fern Cliff, Lee. 



Hybrid forms of Thelypteris. 



T. cristata X marginalis. — Lenox; Washington (C. S. Lewis). 



T. cristata X spinulosa. — Lenox; Washington (C. S. Lewis). 



T. cristata, var. Clintoniana X spinulosa, var. intermedia. — 

 Cheshire (Winslow); Washington (C. S. Lewis). 



T. cristata, var. Clintoniana X Goldiana. — North Adams 

 (Churchill). 



T. Goldiana X marginalis. — Cheshire (Winslow). 



T. marginalis X spinulosa, var. intermedia. — Washington 

 (C. S. Lewis). 



