It must, therefore, be supposed that abyssal forms have gradually acquired such tolerance of darkness as makes their health independent of the sun.
They have a well-developed proboscis which is used as a suctorial organ; some are abyssal, but the majority are either commensals or parasites of Echinoderms.
Thus red clay and radiolarian ooze are distinguished as abyssal deposits in contradistinction to the epilophic calcareous oozes.
From a study of remains of the mollusca, brachiopoda and other marine organisms they will determine the shallow water (littoral) and deep water (abyssal) regions of the surrounding oceans, and the clear or muddy, salt, brackish or fresh character of its inland and marginal seas; and even the physical conditions of the open sea at the time will be ascertained.
In the Abyssal Shelf located in the Hellfire Peninsula, fly on a gryphon or Wyvern to bomb demons from the Burning Legion and stop the dimensional gateways from allowing the introduction of more enemy forces into the area.