Taxa described in 1921

Mastigiidae is a family of true jellyfish. The family is native to the Indo-Pacific, but a species of Mastigias has been introduced to the West Atlantic, and Phyllorhiza punctata has been introduced to the West Atlantic and Mediterranean Sea.

Chioides is a mainly Neotropical genus of skipper butterflies in the family Hesperiidae (Eudaminae)

Codatractus is a Neotropical and Nearctic genus in the family Hesperiidae (Eudaminae).

Neobulgaria is a genus of fungi within the family Leotiaceae. The genus, circumscribed by the Austrian mycologist Franz Petrak in 1921, contains nine species.

genus of fungi

Henrica is a genus of crustose lichens in the family Verrucariaceae. It has four species. These lichens grow as crusts that adhere tightly to limestone, sandstone, and other hard rocks, ranging from paper-thin films to thick, warted layers in subdued colours of white, pale grey, or fawn. They reproduce through black to dark-brown flask-shaped fruiting bodies that contain distinctive brown spores divided into numerous cells like a brick wall, giving them a characteristic appearance.

Sagediopsis is a genus of fungi in the family Adelococcaceae.

Byssolecania is a genus of lichen-forming fungi in the family Ectolechiaceae.

Phylloblastia is a genus of foliicolous (leaf-dwelling) lichens in the family Verrucariaceae. The genus was circumscribed in 1921 by Finnish lichenologist Edvard August Vainio, with Phylloblastia dolichospora assigned as the type species.

Aretza is a species of shorthorn grasshopper from the Acrididae family found in north Australian savannas, particularly in the wet season. They are notoriously difficult to catch or photograph because of their swift movement due to heat produced from the sandstone habitat. left|thumb|A acrididae short-horned grasshopper found on a local cycas species in Litchfield National Park in the Northern Territory of Australia.

Semigyalecta is a genus of lichenized fungi in the family Gyalectaceae. It is a monotypic genus, containing the single species Semigyalecta paradoxa, described as new to science in 1921 by Finnish lichenologist Edvard August Vainio.

Thelidiopsis is a genus of fungi in the family Verrucariaceae.