Student or Learner
"It is comparatively little known," observed Gahagan, "that Pond actually is an oyster. He builds up out of oysters the permanent type or image. Hasty naturalists (I need only name the impetuous Pilk) have repeated the report that he resembles a fish. But what a fish! It was left to the researches of Nibbles, in his epochmaking work, Pondus Ostroanthropus, or The Human Oyster Revealed, to give our friend his high and rightful rank in the biological order.
I don't understand text in bold.
The paradoxes of Mr. Pond - Google Books
... look around page 67.
In the first bold part - Gahagan is saying that Pond is the eptiome of an oyster. (If you look at further evidence in the text, he says that both Pond and oysters have beards - and are alone in having this decoration. He also says that Pond - when closed up, it as closed as an oyster.
In the second bold part, I think the author is being sarcastic. He says that others have compared Pond to a fish, but that 'Nibbles' - through investigation has discovered the truth that Pond is actually an oyster. The title of Nibbles' work is The Human Oyster Revealed.