†family Pollakidae Marshall (glass sponge)
Hexactinellida - Lyssakida - Pollakidae
Parent taxon: Lyssakida according to G. J. Hinde 1883
Sister taxa: Dilatispongia, Holasterellidae, Hyalostellidae, Monakidae
Subtaxa: Hyalostelia
Ecology: stationary intermediate-level epifaunal suspension feeder
Distribution:
• Cretaceous of the United Kingdom (1 collection)
• Carboniferous of the United Kingdom (2), United States (1: Nevada)
• Devonian of Australia (1)
• Whiterockian of United States (2: California)
• Ordovician of Canada (1: Ontario), Peru (1), the United Kingdom (54), United States (6: California, Nevada)
Total: 69 collections each including a single occurrence