XLI. A NEW HYPNUM OF THE SECTION 

 CALIEBGON. 



J. M. HOLZINGER. 



One of the most interesting collecting grounds in south- 

 eastern Minnesota is the place designated in my reports as 

 Lamoille Cave. The spot is some twelve miles below Winona, 

 and about a mile below Lamoille, the railroad station The 

 ''cave" is produced by the undermining of some ledges of 

 St. Croix sandrock, leaving a low cave a rod or two in ex- 

 tent each way, the sandstone roof meeting the floor all around. 

 A small pool of water covers part of the floor, the effect of a 

 spring in one corner. This water slowly finds its way out into 

 the marshy grassland to the north of the cave, through mats 

 of Anacharis, water speedwell, water cress, the musk plant 

 and their associates. It is in this society, along with its dis- 

 tant relative, Brachythecium rivulare, that the plant under 

 consideration was found in considerable quantity. 



Hypnum cyclophyllotuni, n. sp. 



Plants dioecious; dark green above, yellow below; 8-10 c m. 

 high; erect by crowding; stems firm, sparingly beset with 

 small inconspicuous radicles along their entire length. Stem 

 leaves five-ranked, concave, ascending when moist, inclined to 

 be appressed when dry (especially the older leaves, which are 

 also apt to be split part way down from the apex), as broad as 

 long, or broader, obtuse, entire margined, costate to apex; costa 

 broad, 100-120 mik. wide, about 30 mik. thick; leaf angles decur- 

 rent, strongly excavate, their cells abruptly enlarged, hyaline, 

 25-40 mik. wide, 80-100 mik. long, the thin- walled cells not quite 

 reaching the costa, an area of the small chlorophyllose cells of 

 the body of the leaf passing down on each side of the costa; 

 upper leaf cells 8-10 mik. wide, 40-60 mik. long, chlorophyllose; 

 branch leaves, of the short axillary branches, also concave, 



