Thalassites from Le Docteur Oméga (1906) by Arnould Galopin.
"Indeed, a grinning monster … a kind of fabulous man stared at us with his round lidless eyes … huge and protruding.
He clung to the nuts of the projectile and victoriously resisted tub produced by the wake of our vehicle. At one point, he crawled to the front of the shell by using his hands and feet were webbed like those of a cormorant.
We then were able to examine this strange visitor.
It was a good man … but a horrible man, a repulsive, a hundred times more hideous than these strange demons carved on the porches of our old cathedrals …
His face, dark purplish blue, vaguely remembered that a hamadryas … her forehead was smooth and elusive, its broad and flattened nose.
Instead of ears he had two bloody holes similar to the gills of fish …
Its largely split mouth was armed with a quadruple line of pointed hooks which tightened or drew aside according to whether the monster opened the jaw more or less.
However, the color of this strange vertebrate was not uniform and the color of her body contrasted sharply with that of his head.
His chest and stomach were covered with green scales … As for his hands and his feet, they were bright red, which went on darker towards the ends …
This submarine man seemed plagued by a violent rage … he shouted hoarsely, you could hear the walls of the Cosmos the creaking of his claws …”
”- This is really a submarine man, said the doctor, one of those “Thalassites” which Pliny speaks … His description made it absolutely corresponds to the remarks I noted …
"It is presumed that at one time - there is that thousands of years - the seas of our planet were also populated by these monsters that have gradually disappeared or have changed, and the changes in transformations became seals or walruses …"