LAUSR

While collecting epiphytic diatom samples from the west coast of Sweden, a small Mastrogloia species has been observed and could not be matched with any of the described taxa. Based on both light and electron microscopes examination, this species has been described as new, Mastogloia wulffii sp. nov. and included in Mastogloia section Sulcatae. This species is very small with valve length not exceeding 16.3 µm. It is characterized by having a narrow, almost straight median depression on both sides of the sternum-raphe, no marginal ridge and with rounded areolae on valve mantle as well as having completely hyaline lateral sterna. A comparison with similar taxa is given. M. wulffii is a marine species growing in moderate numbers on the red alga Polyides rotunda which is widely distributed along the coast of Vrango Island, Sweden.