I note that the top page includes a "Selmer History" link that might be interesting. I'll have to go back and look at it later.
Links on the woodwind page go to the following:
Selmer Clarinets has some fairly good pictures of typical modern clarinets. Unfortunately, they don't make a "metal" one now. At the bottom of the page is a link to a .pdf that shows some more detailed pictures of wooden and resin clarinets, but be warned that it's rather large (2+ MB) so may take longer to (down)load than is worthwhile.
Discussion mongers may want to bookmark those last two. They're fairly clean reference pictures.
The quick check: - - so far as I've seen, all clarinets have a mouthpiece with a cork ring at the "bottom" that slips inside the mating part on the main instrument. Saxophones have no cork on the mouthpiece, and the mouthpiece goes on the outside of a corked area on the mating part.
Technically, both the sax and clarinet have a "bell," which is a sort of "flare" at the bottom. The main bore of a clarinet is a straight cylinder. A saxophone is conical, and the diameter at the "last pad" on the bottom will be about twice the diameter up at the top of the instrument.
The straight bore on the clarinet means that a "register" is a twelfth. The same fingering, "blown up" to the next harmonic, is an octave plus a fifth (so clarinettists automatically learn to finger in at least two "keys." The conical bore of the saxophone allows it to "register" in octaves - like a pennywhistle.
As a side note, I've seen several such instruments - sax and clarinet - in small museums recently, and every one of the had the mouthpiece on upside down. (Obviously non-musician curators.) The Reed Goes On The Bottom.