22 MOSSES WITH A HAND-LENS _ 



greneral appearance are very similar. But with the sporophyte 

 present the distinctions are clear. In Figs, a, b and d, note that the 

 capsule of the Common Hair-cap is almost cubical, that the lid 

 has a very short beak, and that the capsule is entirely covered 

 by the calyptra. The capsule of the Ohio Hair-cap («) is 

 elongated, slender, with a tapering neck ; lid much longer-beaked. 

 The lid and the calyptra of the Ohio Hair-cap fall early in June, 

 very soon after the spores are ripe, and it is not always easy 

 to find either in position ; but, if the calyptra be found, it will 

 be seen to cover the upper portion of the capsule only. The 

 Common Hair-cap, although occurring in woods, is most com- 

 mon in open fields. The Ohio Hair-cap is most frequent in 

 shady, more moist spots, often in deep woods. 



P. GRACiLE Dicks, is a rare form, which I believe is often 

 confused with P. Ohioense. The length and the number of 

 angles of the capsule are somewhat variable, although the capsules 

 usually have more than four angles. Microscopic sections of the 

 leaves are necessary definitely to determine this species. 



P. JUNIPERINUM Willd., Juniper Hair-cap, resembles P. 

 commune very closely in general appearance except for the 

 light glaucous-green color of its open leaves, so different from 

 the dark green of the latter that they are strikingly distinct at a 

 glance when moist, especially if the two species are growing 

 intermingled, as they often do. It usually grows in drier situ- 

 ations than commune. A glance at the upper surface of the margins 

 of the leaves under a hand-lens will serve to distinguish the two 

 species without the shadow of a doubt. This species matures its 

 spores at about the same time as commune or possibly a little 

 later. 



P. piLiFERUM Schreb., the Awned Hair-cap, has the same 

 light color as the preceding and also has its leaf-margins turned 

 in. but the leaves differ in shape as shown in the figure, and end 

 in long white awns. The entire plant is much smaller than in 

 my of the other species, rarely growing larger than the figure. 

 It also grows in much drier places than the other species, the 

 thin layers of soil around the edges of ledges in dry pastures 

 3eing a favorite habitat. It matures in June and July. 



I have found this species on ledges next the bare rock, next 

 ;t but farther from the ledge the Juniper Hair-cap, and in moist 

 depressions in the ledge the Common Hair-cap, growing on the 

 iccumulated soil and humus. 



