Protologue Description: Hypnodontopsis spathulata H. Akiyama & A, Tanaka, sp, nov. (Figs 1-18)
Affinis Hypnodontopsis apiculata, sed foliis 0.8-1.0 mm longis, capsulis ovatis, dentibus peristomaico lanceolatis, calyptris cucullatis diversus.

Plants small, bright green, gregarious on tree trunk. Stems ca. 0.5-1.5 mm high, erect, simple. Leaves oblong to spathulate, apiculate, 0.8-1.0 mm long, 0.25-0.3 mm wide at the widest portion, loosely and spirally appressed when dry, erect-spreading when moist; margins plane, crenulate with papillae; costa ceasing just below apex, with two layers of stereids and one layer of large, thin-walled cells in a transverse section; upper lamina cells round to hexagonal, 5-10 X 5-10 µm, chlorophyllose, thick-walled, with 3-5 papillae on both surfaces; lower lamina cells much larger than upper ones, hyaline, rectangular, smooth, forming a distinct region with thicker transverse walls than longitudinal ones. Fusiform propagules abundant on the adaxial surface of leaves, dark brown, composed of 8-16 cells.
Sexuality unknown. Perichaetia terminal. Pericheatial leaves almost similar to vegetative ones, with innermost several leaves longer and loosely surrounding sporophyte. Perigonia not seen. Calyptra cucullate, covering upper 1/3 of the capsule, pale yellow, smooth, entire or with a few hairs at the base.
Seta ca, 0.6 mm long, smooth, strongly spiraling in both dry and wet conditions. Capsules immersed among leaves when dry, shortly exserted above the leaves when moist, straight and symetric, about 0.6 mm long, ovoid, with deeply 8-ribbed and contracted below the mouth when dry, elliptic to subglobbose when moist. Opercula small, almost flat, ca. 0.1 mm in diameter; dropped-off with calyptra in March. Annulus pale, arranged in single row. Exothecial cells rectangular, with thicker longitudinal cell walls than transverse ones. Stomata absent. Peristome in a single row, open when dry. Peristome teeth pale yellow, arranged in 8-pairs, inserted deep within the mouth, broadly lanceolate at the base and linear-lanceolate at the upper portion, with distinctly developed pallisade-like markings on both surfaces. Spores ca. 30 µm in diameter, spherical, minutely papillose or almost smooth.
Specimen examined. Myanmar, Chin State, Natma Taung National Park, in the vicinity of Kanpetlet, ca. 1750 m alt., coll. Murata et al. 22245 (holotype in HYO; isotypes in CONN, HIRU).
Habitat. Forming a sparse colony on a tree trunk along a trail in open Pinus savannah. Sporophytes become mature around March (in the middle of the dry season).