fragilariforma fragilariforma fragilariforma is a genus of diatoms belonging to the family fragilariaceae. fragilariforma scientific classification domain: eukaryota clade: diaphoretickes clade: sar clade: stramenopiles phylum: gyrista subphylum: ochrophytina class: bacillariophyceae order: fragilariales family: fragilariaceae genus: fragilariformawilliams and round, 1988 extant species see text the genus was first described by d. m. williams and round in 1988. the genus has cosmopolitan distribution. species: fragilariforma bicapitata fragilariforma neoproducta fragilariforma virescens fragilariforma virescens