(ox-ner-ell-a) is a centrohelid heliozoon - the most speciose group of heliozoa. As with other heliozoa, it has radiating arms which intercept swimming prey which are captured by the extrusomes (the lumps on the arms) and then ingested. This genus includes spicules with fine spicules. Those spicules may be so delicate as not to be readily visible (if at all) by light microscopy. Heterophrys
is similar but has delicate organic spicules. These may be very hard to see by light microscopy, and this can easily lead to misidentification. Phase contrast.