The mouth was closed so tightly that the lips were invisible.

The nose was flat.

The eyes, like those of a fish, were round and staring.

There was no expression whatever in the features.
The mysterious monster had risen quite close to the boat.
Ludwig seized an oar with both hands to crush the monster's head; but the heavy blow fell on the water.

The creature had vanished underneath the boat, and only the motion of the water on the other side indicated the direction it had taken.