These auger bits average 30 inches long with the cutter on the bottom which is flat except for the cutter. There are 8 sizes, all Sorby except one which has a round shaft while the others are square. The handle fits the tang and is made of oak with a heavy brass section around the middle.
I have heard them refered to as doweling bits. I have a few kicking around some where but I don't recall ever trying one
Also called spoon bits from the shape.
Is there a cutting lip on the bottom? I cannot tell from the photo. They look like nose bits or nose augers to me, which have a cutting lip on the bottom. They are used to cut very straight holes across grain. They are typically used by shipwrights, carbuilders (rr), chairmakers, barn buildings, wherever you need a really straight hole across the grain. Based on the single handle and the very long shanks, I would set that is a shipwright's auger set. They are also called pod augers. Anything like that is a variety of a shell auger, as are spoon bits.
Yes, the cutting lip is on the bottom and the sides are not sharp.
The side that trails the nose should be sharp. They are usually beveled on the inside of the shell. I misspoke about the pod augers. Those usually are auger sized and look like short, fat spoon bits.