Hmmm... reminds me of a poem called the Orc Marching Chant
Sauron made some rings and they were very usefu things,
And he only wanted one to keep,
But Isildur took the one just to have a little fun,
Sauron's finger was inside, What a creep!
So according to this Isildur took the ring along with the finger. The finger was probably lost with the ring but unlike the ring it was never found. Maybe if Degol had let the fish put him a little farther he would have picked up a finger instead of the ring.
