Sea creatures on the beach - can you identify? (need answer fast!)

Factual Questions
1

I don’t really need the answer fast, but I won’t complain if someone nails it right away.

My mom took some pictures of a couple sea creatures that washed up on the beach near Fort Myers, Florida this week (mid-March, if you’re reading this thread a while from now). She’s curious as to what they are, and I couldn’t help her beyond saying the obvious (“They’re sea creatures, Mom”).

First, there’s this worm-like thing. The only things I know about it, besides what it looks like, are “they’re everywhere,” “the gulls love them,” and “when you step on them, guts squirt out” (“Thanks for the extra visuals, Mom”).

Then there’s this cucumber-shaped thing. She didn’t mention anything about their ubiquity, tastiness, or gut-squirting properties (“Thanks, Mom”).

Any Dopers recognize either of these? Any aid in identifying them is highly appreciated. Thanks much.

2

I think that’s a parchment worm in its case. They get washed out of their burrows and end up on the beach.

It looks like some kind of sea cucumber, but I’m not sure which species.

3

I think you linked twice to the same URL.

4

Thanks, Colibri. Dopers come through again!

If someone else can ID the particular variety of (presumed) sea cucumber in the second picture, my Mom will be very happy.

5

My bad. Here is the correct second link.