Neotessella

Colonial genus, having the cells arranged in the periphery of spherical colonies. The colony is surrounded by a mucilaginous envelope, consisting of a layer of elliptical, overlapping scales. The cells possess two flagella and two brownish chloroplasts. Stigma is absent.

The genus so far includes only two species. Neotessella volvocina, the type species of the genus, is known only from Australia. The second species, Neotessella lapponica, is distributed mainly in Northern temperate and subarctic regions (Europe, Russia, North America).

A. Neotessella colony surrounded by a mucilaginous envelope consisting of a layer of siliceous scales. C. Oval scale with a central spherical protuberance (N. lapponica).