There, at a depth to which divers would find it difficult to descend, are...

There, at a depth to which divers would find it difficult to descend, are caverns, haunts, and dusky mazes, where monstrous creatures multiply and destroy each other. Huge crabs devour fish and are devoured in their turn. Hideous shapes of living things, not created to be seen by human eyes wander in this twilight. Vague forms of antennae, tentacles, fins, open jaws, scales, and claws, float about there, quivering, growing larger, or decomposing and perishing in the gloom, while horrible swarms of swimming things prowl about seeking their prey.
To gaze into the depths of the sea is, in the imagination, like beholding the vast unknown, and from its most terrible point of view. The submarine gulf is analogous to the realm of night and dreams. There also is sleep, unconsciousness, or at least apparent unconsciousness, of creation. There in the awful silence and darkness, the rude first forms of life, phantomlike, demoniacal, pursue their horrible instincts.