291 
DESCRIPTIONS of NEW and RARE SPECIES. 
Barbula Nicholsoni Culmann. 
The following is a translation of the Latin diagnosis by Dr. 
Culmann: Revue Bry., 1907, p. 100. 
Dioicous, female flowers terminal, male flowers and fruit wanting. 
Habit of Barbula rigidula or spadicea ; tufts brownish or olive-green ; 
stem 1 to 2’5 cm. long, furnished towards the apex with numerous 
parapliyses, straight branched, central strand distinct, cortical cells 
incrassate, intermediate cells collenchymatous. Leaves when moist 
recurved, finally erect, almost incumbent, lanceolate from an ovate 
base, acute, margin revolute except at the apex ; marginal cells in 
two layers to the apex. Upper cells of the leaves scarcely incrassate, 
densely covered with low papillae, small (lumen 0.006 mm.) roundish, 
lower cells quadrate or shortly rectangular, 0.008 to 0.009 mm. broad, 
and of equal length, towards the base two or three times longer, not 
or slightly incrassate. Nerve thick, prominent at the back, confluent 
at the apex with the incrassate marginal lamina. Prominent thin- 
walled cells, (“deuter cells”) four or five, distinct, supported by a 
bundle of small thick-walled cells (“stereid cells”) in one or two 
layers. 
Riccia pseudo-Frostii Schffn. 
Monoicous. Thallus twice as large as in R. Hubeneriana and of 
very different appearance, very similar to that of R. Frostii, 5—7 
mm. long, and 1 mm. broad, thick, yellowish green to pure green on 
both sides, reddish here and there on the tolerably sharp and thin 
margins, pitted on the upper surface in the older part with numerous 
air-spaces open above, variously and not very regularly divided, 
spreading in fan- or rosette-shaped rosettes 1—2 cm. in diameter, 
branches numerous, in part arranged closely parallel to one another 
and in part overlying one another with rounded and emarginate ends. 
Transverse section quite different from that of R. Hubeneriana , one- 
and-a-half to twice as broad as high, convex below; the abruptly 
perpendicular sides pass into shallow arcs in the feebly indicated 
horizontal wings. Upper side with a slight channel diminishing 
