(i 4 o) 



Dawson, in swamp water, in fine fruit July 17, 1S9S (746). 



Hxpnum falcatum Brid. About springs at head of Lake 

 Bennett. Leaves nearly entire or serrulate slightly below. 

 Median cells about .004 mm. wide and .030 to .060 mm. 

 long and cell walls all thickened (748). 



Hxpnum crista-castrensis L. Lake Lindeman and Klon- 

 dike River bottom. Not found in fruit (750). 



Hxpnum reptile Michx. Dawson, on rock. Median leaf- 

 cells .004 by .030-. 040 mm., scarcely vermicular, alar cells 

 short oblong to quadratic. Leaves not decurrent (756). 



Hxpmun hamulosum B. & S. Dawson. At base of trees 

 in damp places. These specimens are rather more robust 

 than usual with longer and more narrowly pointed peri- 

 chaetial leaves. Cross sections of stem are oval, about .200 by 

 .160 mm. This is smaller than given by Limpricht (.300- 

 .350 mm. long), but no. 491, Raben. Bry. Europ., cited by 

 him, shows sections similar to mine in every way. The thin 

 outer cells of the stem have the exposed surfaces mostly 

 sunken in or worn way giving the surface a rough, papillose 

 appearance in cross section. The thickened cells next the 

 outer wall are in 3 or 4 rows. Central strand distinct. The 

 leaves are more or less plicate and border revolute below on 

 one side (754). 



Hxpnum subplicatilc (Lindb.) Limpr. Lake Lindeman, 

 on damp rock and earth. This plant is very close to calli- 

 chroum but differs in being rather smaller with regularly pin- 

 nate branches, leaves wider just above the base and abruptly 

 narrowed to the insertion and capsule shorter. Cross sec- 

 tions of stem show an indistinct central strand and walls of a 

 row of thin outer cells next about 3 rows of thick-walled 

 cells. Median leaf-cells slightly vermicular, about .005 mm. 

 wide and .040-. 060 mm. long, alar cells mostly forming a 

 small but distinct, convex, pale cluster. Stem leaves entire, 

 borders flat, terminal branch leaves minutely serrulate, peri- 

 chaetial leaves gradually narrowed to long, serrulate, slender 

 point. 



According to Limpricht this species has been previously col- 



