Bysmatrum granulosum sp nov., a new benthic dinoflagellate from the southwestern Indian Ocean

A new benthic marine dinoflagellate, Bysmatrum granulosum Ten-Hage, Turquet , Quod & Coute, sp. nov., was obtained from sediment and coral samples from sites of La Reunion Island (SW Indian Ocean). This new species is describe d and illustrated by light and scanning electron micrographs. Cells are 40- 50 mum long and 40-46 mum wide. The epitheca is conical and smaller than th e hypotheca, which is trapezoidal with convex sides. Plate tabulation is ty pical for the genus (P-0, X, 4 ', 3a, 7 ", 6c, 5s, 5 ' ' ', 2 ' ' ' '); epi thecal plates 3 ' and 4 " separate the intercalary plates 2a and 3a. Thecal plates are perforated by pores and covered by both small and minute wart-l ike projections, linearly arranged, radiating from the apical pore. This ne w species differs from the three others of the genus Bysmatrum in the follo wing characters: cell shape and size, size of the apical pore complex and f eatures of thecal plates (plate shapes and ornamentations).