Sentence:  I confess to having felt a prejudice against sleeping in a bag, more especially a <WSD>sheepskin</WSD> bag, which would probably have a muttony odor; but it was pronounced to be the warmest and least cumbersome form of bedding we could have ... 
Meaning of the word marked with <WSD> tags:  The skin of a sheep, especially when used to make parchment or in bookbinding.