-85- 



acuminate and for the most part finely denticulate, and finally, by its small 

 quadrate alar cells, the median ones shorter. 

 Hypnum uncinatum polare Ren. 



In habit resembling a variety of plumosnm. but the basal areolation is 

 laxer, parenchymous, median cells shorter, more chlorophyllose. 



From St. Matthew Island (Trelease, 2159); Plover Bay, Siberia (Trelease, 

 1977). 



Hypnum sulcatum stenodictyon Ren. 



Distinguished from the typical form by the closer areolation and nar- 

 rower cells. 



From Muir Glacier (Trelease. 2019). 

 Hypnum subeugyrium occidentai.e Card, and Ther. 



Differs from the typical form of the new world as a rule, in the broader, 

 softer, more concave leaves, entire apex, slightly larger alar cells forming 

 sometimes subinflated auricles but always much less distinct than in H. 

 eugyrium. Costa sometimes subsimple. 



From Hidden Glacier Inlet, Yakutat Bay (Trelease, 1784); Muir Glacier 

 (Trelease, 1805). 



Hypnum sarmentosum Beringianum Card, and Ther, 



Differs from the typical form in the more slender stems, more laxly foli- 

 ate, in the broader costa and especially in the much smaller usually quadrate, 

 scarcely dilated alar cells. 



From St. Matthew Island (Trelease, 1888, in part 1889). 



By the structure of the angles of the leaf, this moss comes near H. drun- 

 neo-fuscum C. Muel from the Chukchi Peninsula, but the latter has a differ- 

 ent facies, a closer areolation and a much thinner costa. 

 Hypnum plesiostramineum Ren. 



Tufts loose, soft. Stems slender, erect, 4-6 cm high, simple or spar- 

 ingly branched, branches slender. Leaves quite crowded, erect, only a little 

 spreading at apex, about 1.4 mm. long. .6 broad, various shapes, the 

 lower ovate-oblong or subdeltoid, acuminate, subobtuse, the upper eliptical 

 with a broader and more obtuse acumen, the branch leaves ovate, round- 

 obtuse, all plicate, slightly sinuate, plane margins. Costa thin, extending 

 about three-fourths or further, 40-50// broad at base, alar cells large, lax, 

 hyaline, forming inflated beautifully distinct auricles, the median narrowly 

 linear, fiexuous prosenchymatous, 40-60// long, 5-6 broad, the apical shorter 

 ovate or subhexagonal. Other characters unknown. 



From Yukon River (W. H. Dall, in 1867). 



This species resembles H stramineum Dicks, and H. pseudo-stramin- 

 eu7n C. Muel., but it is with the latter that it has the closest affinity. It dif- 

 fers from it by its leaves being shorter, subdeltoid, with a costa thicker 

 (40-50/^ instead of 30-40). longer, usually exceeding the three-fourths, and 

 finally by the firm areolation formed of fiexuous cells, rather obtuse (not 

 truncate) at the ends, with thick walls, and resembling those of Hygro- 

 hypnum. 



Note 3, p. 347)— A preliminary diagnosis of this moss has been published 



