Microthamnium. | 17. STEREODONTE X. 505 
pens, pinnatim ramosus. Folia compressa, patenti-divergentia, concava, 
ramea ovata acuminata, marginibus minute serrulatis, cellulis omnibus 
parvis elongatis dorso papillatis; perichetialia ovata, sensim longe subu- 
lata, patentia, paraphyses elongatas includentia. Theca in pedunculo 
rubro horizontalis, ovali-cylindracea, operculo conico brevirostrato, peri- 
stomii interni ciliis duobus inter processus zquilongis; calyptra parce 
pilosa. 
Hab. Mexico, Leiboldt; Venezuela in valle di Aragua, Humboldt et 
Bonpland. Fl. Amazon, Sellow. Brasilia tropica, Burchell, n. 1184, 
Gardner, n. 115, 127. Ins. Stæ. Catharinæ, Pabst; Rio de Janeiro, Milne, 
M*Gillivray. Prope Constitutao ad arborum truncos et ligna putrida in 
sylvis (2000 ped.), Weir,n.35. Inter S. Paulo et Jundiahy ad lapides et 
arborum truncos (2000 ped.), Weir, n. 94. 
Caules depressi. Folia viridia, nitentia, lutescentia, et sicca et humida 
plicata. Thecæ forma varians nunc gracilis, nunc abbreviata latiorque. 
C. Müller refers to this species two others before described by 
himself as distinct — Hypnum filidens, * Bot. Zeit.’ 1844, p. 742, and 
H. erythrodontium, l. c. ; it is not, however, improbable that another 
allied species exists, as he describes the inflorescence of H. elegan- 
tulum as dioicous. 
4. M. oxypoma (Schwegr. t. 259, Hypnum). Caulis repens, vage 
ramosus, ramis in ramulos breves pinnatim divisis, lutescentibus squar- 
rulose foliosis. Folia sparsa, densiuscule conferta, patula, parvula, con- 
cava, valde pellucida, pallide viridia, e cellulis oblongis superne angusti- 
oribus areolata; perichzetialia squarrulosa, in acumen longiusculum pro- 
ducta. Theca in peduneulo mediocri levi apice parum arcuato horizon- 
talis, oblonga, junior teres parum inzqualis, luteo-fusca, operculo conico 
recte acuto concolori; peristomii dentes exteriores ferruginei, interiores 
flavi solidi, ciliis singulis longis articulatis pallidioribus.— C. Müll. Syn. ii. 
453. 
Hab. Brasilia, Pohl. 
An ab M. elegantulo diversum ? 
5. M. oxvsTEGUM (Spruce). Folia compressa, patentia divergentia- 
que, ramea late ovata, acuta, concava, serrulata, cellulis elongatis dorso 
papilliferis ; perichzetialia a basi parva latiore longe subulata, flexuosa, laxe 
erecta. Theca in pedunculo rubro, ovalis, horizontalis, inzequalis, collo 
sensim attenuato, operculo conico acuto, peristomii dentibus luteis intus 
trabeculatis, interni processibus angustis carinatis zequilongis, in membrana 
fere usque ad dentium longitudinis medium exserta impositis. 
Hab. Andes Peruvianz, Tarapoto ad rivulum Shillicaio (1800 ped.), 
Spruce, n. 1082, 1083; ad rivulum Aquashiyacu prope Tarapoto (2000 
ped.), Spruce, n. 1085; in monte Campana (4000 ped.), Spruce, n. 1091; 
ad rivulum Shillicaio (1800 ped.), Spruce, n. 1092. 
