What this coin looks like (obverse, reverse, mint mark location, special features, etc.): There are a number of 1849 Seated Liberty Half Dime overdate errors. There is also much confusion and debate among experts in the numismatic field whether the dates are actually 1849/8 (1849 Over 1848) or 1849/6 (1849 Over 1846). This is mainly due to the difficulty in determining what digit is actually underlying the "9" in the date. In more recent times the consensus has been leaning towards the 1849/6 overdate error. Depicted above is a few examples of the date varieties vs the normal date. Source of image on bottom-left is courtesy of Heritage Auctions. Source of image on bottom-right is courtesy of NGC Coins.