Scrippsiella spinifera sp. nov. (Pyrrhophyta) is described using light and scanning electron microscopy. The species was first found in the Gulf of Trieste (Italy, Northern Adriatic Sea). The cells are 30-52-mu-m long and 21 - 36-mu-m wide. The epitheca is conical and the hypotheca trapezoidal with short spines at its terminal part. The plate tabulation does not differ from other Scrippsiella species. The thecal plates are perforated by numerous pores surrounded by concentric ridges. A taxonomical discussion and a comparison with the other species of the genus are made.
