“Oh, different big fish—­a sea lion, alligators and turtles,” said Mr. Bobbsey.

“Let’s look at the sea lion!” called Flossie.

“I want to see a swimming turtle,” said Freddie.  “I had a mud turtle once, but he went away.”

“You shall see everything,” promised Mr. Bobbsey.

They went over to the pool, where a number of large alligators, and one crocodile, were lying in or out of the water.  Some were lazily swimming about, and the crocodile was asleep out on the stone ledge, with his big mouth wide open.

“He’s waiting for some one to come along and feed him,” said Bert.

“I guess he’d eat a lot,” laughed Freddie, looking at the rows of big teeth in the crocodile’s mouth.

They passed on to the pool of the sea lion.  That sleek, brown animal was swimming about like a big fish, now and then stopping under one of the pipes where the water ran into his pool, and holding his mouth under the little stream as though taking a drink.  Now and then he barked like a dog.

Around the stone ledge, or wall of the pool, was a wire grating, and near the floor was a sort of pipe running all around, so the smaller children could step up on this to look in—­something which the big folk did not have to do.

“Be careful!” cried Nan, as Flossie leaned well over the edge to get a better look at the sea lion.  “You might fall in.”

“She could get a ride on his back if she did,” said Freddie.

“Well, I’m not going to!” exclaimed Flossie, drawing back, a little frightened, as the seal splashed the water right under her, some drops going in her face.

They watched the seal for a while, went over to the other tanks, where some sturgeon and other big fish swam about, and then Freddie called: 

“I want to see the big turtles!  Where are they?”

“Over here,” said Mr. Bobbsey, leading the way toward the south end of the building near the tank, where the green moray—­a sort of big eel—­was lying half in and half out of a piece of sewer pipe put in his tank to make him feel more at home.  “There are the big turtles,” and Mr. Bobbsey lifted Flossie up over the rail so she could look down more easily.

There were some very large turtles in the tank, swimming by moving their broad flippers.  Sometimes they would swim about close to the white tiled bottom of the tank, but the water was clear, so they could be seen easily.  Again the turtles would rise to the top, so that their big, hard shells were out of water, like a raft which the boys build to play with when the city’s vacant lots or country meadows are flooded in the Spring.

In one end of the tank was a big turtle—­the largest of all—­swimming by himself, and overhead, hung by a wire from the room, was a stuffed one, larger yet.  This, so a sign near it said, was a “leather-back turtle,” and when alive had weighed eight hundred and fifty pounds.