Guide to Mastogloia

The valves of Mastogloia are elliptic to elliptic-lanceolate or lanceolate, with rounded to capitate ends. The valvocopula (first girdle band) each possess complex silica chambers, called partecta, that function to secrete strands of mucilage. The raphe is straight or undulate. The axial area is narrow, with a slightly expanded central area. Living cells have two plastids.

Mastogloia is primarily a marine genus. A few species are found in inland waters, typically in benthic habitats. The genus appears to be closely related to Aneumastus, based on a similar, but less complex, valvocopula.

Hustedt (1933) reviewed all species of Mastogloia (not just European) and provided a key, which he organized around artificial several groups (Gruppen, including freshwater), emphasizing that these groups had no taxonomic significance. Stephens and Gibson (1980) reaffirmed and supported this point, but some authors have treated them as formal Sections, and assigned new species to them. Since most new species refer back to species in Hustedt (1933), Novarino (1989) prepared a resemblance list for species published between those dates but this list is now considerably out of date.