MOSSES WITH A HAND-LENS 59 



of our range especially along rivers, extending north to southern 

 Vermont. This is our only species with curved seta, and even 

 in this a portion of the setae seem almost erect. In the dried 

 specimens the capsule appears more fully exserted than is indi- 

 cated in the figure. This is the only one of the species here 

 treated that has plane leaf-margins. 



RHACOMITRIUM. 



R. ACICULARE (L.) Brid. is one of our common mosses 

 occurring around waterfalls and on wet rocks in cool and in 

 elevated situations. Plants large, I to 3 inches long, and very 

 stout ; the broad leaves broadly obtuse, entire or denticulate at 

 apex with small distant teeth, characterize this species so dis- 

 tinctly that no further description is needed, except that given 

 by the plate. The leaf-characters are so distinct that this 

 species is easily recognized with a hand-lens. The spores mature 

 in spring, but well-developed capsules are found in autumn. In 

 this species as well as in most others of the genus nearly an 

 entire year seems to be needed for the complete development 

 of the sporophyte. 



R. FASCICULARE (Schrad.) Brid. grows in rather close flat 

 patches, yellowish green above, black or brownish below, bearing 

 very numerous short obtuse lateral branchlets (see PI. XVI) ; 

 leaves lanceolate, nearly or quite obtuse, without hyaline point; 

 costa faint, vanishing below the apex; peristome teeth divided 

 to the base, spores maturing in spring. Most likely to be con- 

 fused with microcarpum, but easily distinguished by the total 

 absence of hair-points. Common in alpine or subalpine regions, 

 but not likely to be met with elsewhere. 



R. MICROCARPUM (Schrad.) Brid. resembles the last in gen- 

 eral appearance, but with leaves shorter and having a stronger 

 percurrent costa and hyaline-tipped leaves (in the perichsetial 

 leaves the costa ceases below the apex and the apex is some- 

 times obtuse without hyaline tips, making a puzzling combina- 

 tion), hyaline apex of leaves denticulate; capsule smaller and 



PLATE XIV. Grimmia Pennsylvania (From Sulliv. " Icones "). 

 i. Plants natural size. Figs. 15, 16 and 17. Antheridial buds, perigonial 

 leaf, and antheridium respectively. The other figures are self-explanatory. 

 A number of the figures require a compound microscope for their 

 demonstration. 



