Manchester Memoirs, Vol. Ixv. (192 1), No. 1 3 



Mastigolejeunea — ( ?). 



Observations. — I picked out 3 or 4 broken stems of a 

 species belonging- either to this genus or Thysananthus 

 Lindenb. ; leaves oblong, acute, lobule oblong-quadrate ; 

 underleaves entire, broadly cuneate, apex retuse, some emar- 

 ginate. I saw one young underleaf bifid ; no species belong- 

 ing to either of these genera with these characters are recorded 

 from West Africa ; it is probably a new species, but more 

 material is wanted to make sure. 



Marchesinia excavata (Mitt.), St. 



The few stems met with agree well with Mitten's descrip- 

 tion and figures, where all the leaves are drawn as bi-apicu- 

 late ; in my specimens they are either all so, or simply 

 apiculate, stem about 8 narrow cells wide, leaves oblong, .8 mm. 

 by .6 mm. (Stephani says " ovato-ligulate "), upper margin 

 round, ampliate, covering or crossi'ng the stem, often recurved 

 at the base ; lobule oblong-quadrate, angle acute or rounded, 

 complanate above, keel slightly swollen ; underleaves con- 

 tiguous, orbicular, slightly decurrent. 



Drepanolejeunea — ( ?). 



Sterile. Minute, pale green. Stems simple, viewed anti- 

 cally a little more than 2 cells wide. Leaves contiguous or 

 slightly distant, slightly concave, contorted, lobe patent- 

 divergent (70 ), semi-ovate-oval, upper margin arcuate, ex- 

 tending to stem but not covering it, narrow base insertion, 

 lower margin slightly curved, apex acute, the whole margin 

 of leaf minutely denticulate, rarely crenulate, cuticle smooth, 

 lobule patent (50 ) about one-third smaller than the lobe, 

 rotund or oblong-rotund, free margin involute, unidentate, 

 tumid, keel smooth ; cells roundish, very small to small, walls 

 thick, no trigones, marginal cells triangular, acute, teeth 

 unicellular. Underleaves slightly broader than the stem, 

 broadly obovate or cuneate, bifid to the middle, segments 

 acute, 1-2 then 3 cells wide at the base. 



Dimensions. — Stems ^th to J inch long, .04 mm. diam. ; 

 with leaves .65 mm. wide ; leaves, lobe .375 mm. by .3 mm., 

 .35 mm. by .25 mm., .3 mm. by .25 mm. ; lobule .15 mm. long 

 by .1 mm. high; cells .02mm. by .015mm., .02mm. by 

 .02 mm. by .02 mm., marginal teeth .02 mm. by .015 mm.; 

 underleaves .075 mm. by .075 mm., .05 mm. by .05 mm., seg- 

 ments .03 mm. 



