1898] Macoun — Cryptogamic Flora of Ottawa. 27 



cells thick in axile parts, cavernose, becoming at the margin gradually 

 3 or 2-stratose, now and then glandular thickened ; surface cells dis- 

 tinct, translucent, lightly protuberant, subrhombic, trapezoidal, or 

 oblong-pentngonal 3575 x 30'35 mik. ; Nostoc colonies spherical ; 

 monoicous ; anthtridia in groups of 3 or 4 ; involucres short, sometimes 

 united in pairs cylindrical oblong, or by contraction at base and mouth 

 dolioform or subglobose, '85-1 25 x ■5-9 mm., incrassate except at the 

 thin erose or subentire mouth ; capsule black, erect or a little curved, 

 36 X 3-'5 mm., thick-walled, with numerous stomata, the valves rigid or 

 slightly flexuose when dry, brittle and often broken ; columella some- 

 times appendiculate ; spores fuscus or black, rounded-tetral edral 

 densely and rather minutely muriculate on both the inner and outer 

 faces, 48-65 mik. in maximum diameter ; sterile cells short, nearly as 

 broad as long, without spiral thickenings, separate or variously adherent,- 

 often shriveled and inconspicuous. 



On earth subject to inundation along the discharge of Leamy's 

 Lake, near Hull, Que., ?ept. 24th, 1891. 



XXV. MARCHANTIA, Marchant. 



268. M. polymorhpa, Linn. 



Quite common around springs and on earth along the borders o^ 

 svvamps around Ottawa. On earth, by the lake in McKay's \Vood«; 

 April 28th, 1896. 



XXVL PREISSIA, Nees. 



269. P. commutata, Nees. 



Under dripping limestone rocks under the cliffs near the old mill, 

 east side of Rockcliffe, May 7th, 1896. 



XXVIL CONOCEPHALUS, Necker. 



270. C. conicus, Neck. 



Quite common on old logs and earth by brooks around Ottawa. 

 In a swamp on the rear of Cowley's Farm, west of Hintonburg, April 

 i8th, 1896. 



XXVHL GRIMALDIA, Raddi. 



271. G- rupestris, (Nees.) Lindenb. 



On calcareous earth in crevices of rocks near Governor's Bay, Rock- 

 cliffe Park, May 20th, 1884. 



XXXIX. RICCIA, Micheli. 



272. R. arvensis, Aust. 



On damp earth covered by the spring floods around the east side 

 of Leamy's Lake, Hull. Que., Sept. 24th, 1889. 



