257 
Trichostomum arcticum nov. sp. 
Descripsit B. Kaalaas. 
Dioicum, babitu Didymodonti rufo consimile, ro- 
bustum, cæspitosum;? cæspites incobær entes facileque 
discedentes, superne olivacei vel flavo-virides, intus 
fusci. 
Caulis ad cm. 3,5 longus, fuscus, siccus valde 
fragilis, { .sat crassus, 0,18 — 0,25 mm. in diametro rue- 
tiens, erectus vel adscendens, inferne in ramis pluri- 
bus longis simplicibus vel dichotomis divisus, eradicu- 
losus, inferne nudus vel reliquiis foliorum obtectus, 
dimidia parte suprema dense subæqualiterque foliatus. 
Sectio transversa caulis obscure pentagona vel 
fere rotunda; fasciculus centralis bene evolutus, e cel- 
lulis parvis, lutescentibus, tenuimembranaceis construc- 
ts; cellulæ periphericæ in stratis duobus luteo-fuscæ 
vel brunneolæ, minores, bene collencbymaticæ; omnes 
ceteræ majores, parietibus fuscescentibus, corpusculis 
nidulantibus impletæ. 
Folia sat , densa, fere æquimagna, suprema solum 
paullo majora, sed baud distincte comantia, sicca fere 
recta leniterque rappressa vel erecto-^ atentia et le- 
vissime crispata, valde fragilia, unde raro integra, 
bumectata prim urn lente recur vantia, dein patentia di- 
midioque superiore reflexa leviterque crispula, e basi 
angustata lanceolata vël lineato-lanceolata, 2,5 — 2,9 
mrjr. longa, longe tenuiterque acuminata, canaliculata, 
margine plana vel bine illinc paullum undulata, raro 
in medio vel versus basin partim reflexa, integra. 
Costa mediocriter crassa, longe ultra medium 
æquilata, luteola, in apice folii excurrens vel sæpius 
in mucronem byalinum — lutescentem tenuissimum usque 
ad 0,27 mm. longum producta, sublævis, biconvexa vel 
fere plano-convexa postieeque rotundata, 0,065 — 0,050 
mm. lata et 0,035 — 0,042 mm. crassa; sectio ejus trans- 
versa ostendit duces medianos 6 — 8 et duo strata ste- 
Bot. Not , 1900 . 
18 
