Its members have small amebocytes that carry food to the gelatinous mesohyl from their feeding cells, which have a flagellum surrounded by a collar.
"Glass" species of this phylum's class Hexactinellida have silica structural elements. Its members have small amebocytes that carry food to the gelatinous mesohyl from their feeding cells, which have a flagellum surrounded by a collar. Those feeding cells, called choanocytes, line these organisms' inner chambers, whose outlets are called osculua. These sessile suspension feeders have structures based on spicules and were once used as cleaning tools. For 10 points, name this phylum of porous organisms, the simplest animals, which are also called sponges.
"Glass" species of this phylum's class Hexactinellida have silica structural elements.
Porifera [or poriferans; or sea sponges before mentioned]