Class Dinophyceae Pascher (1914)
   Order Peridiniales Haeckel (1894)
     Family Pyrophacaceae Er. Lindem. (1928) see Family Pyrocystaceae (F. Schütt) Lemmerm. (1899)
       Genus Fragilidium Balech ex A.R. Loebl. (1965)
         1475 Fragilidium fissile Balech (1990)
         1476 Fragilidium heterolobum
         1477 Fragilidium lacustre (Lindemann) Balech (1988)
         1478 Fragilidium mexicanum Balech (1988)
         1479 Fragilidium subglobosum (von Stosch, 1969) Loeblich, 1980