These big boys- some with stalks up to five or six inches long and, easily, an inch in diameter- were found attached, en masse, to a Tsunami Buoy pulled out of the middle of the Atlantic Ocean. The fleshy "member" (sorry) is called a PEDUNCLE which, frankly, has to be one of the best words ever. These particular peduncles are big enough that you might refer to them as honkinbadonkapeduncles (ooh- I'm copyrighting that!).
Here are the goose barnacles covering the buoy.
The shelled portion is referred to as the Capitulum (Latin for "head") and the various calcareous plates that make up the head include the Tergum, Scutum and Rostrum (amongst a couple of others but I like to say these in particular). Here is a picture of the Capitulum with the barnacle's thoracic appendages (legs) reaching out to you.
It was actually quite sad to see hundreds of these guys stretching their little, feathery legs out to the ozone but, ALAS! Instead of touching their precious briny deep only air- "air, air everywhere and not a drop of dissolved oxygen or plankton to drink" (isn't that how the quote goes?).
Yes, very, very sad... until they started to stink and then I was able to comfort myself with the tried and true "all in the name of science" maxim.
Way to be gross, barnacles!