Thursday was the marked date on the NFL calendar for the league's supplemental draft. In case you're not familiar with the event, it is a pint-sized version of the NFL Draft that is held in April and with much less fanfare. Usually, the prospects that enter the league by this route are players that have become academically ineligible at their respective universities, have off-field issues and/or made up their minds about entering the league past the draft declaration deadline.
This year's crop of supplemental draftees included two wide receivers (O.J. Ross and Dewayne Peace), three defensive linemen (James Boyd, Nate Holloway, and Toby Jackson) and defensive back, Damond Smith. If a team wanted one of these players, they would have to surrender a draft pick from that corresponding round in the following year's official draft.
Per multiple sources (first announced by the NFL's twitter account), no teams thought that that price was worth it, as not one of those players were selected in this year's supplemental draft. All six are now eligible to sign with a team as an undrafted free agent. In an interestingly related note, Ross was originally signed by the Green Bay Packers as an undrafted free agent after the draft in April, but then the league declared him ineligible for the league at that time.
The last time that the Bengals made a selection in the supplemental draft was back in 2006 when the team used a third round pick on linebacker Ahmad Brooks. He stayed in Cincinnati through the 2007 season and has since had a renaissance in San Francisco with the 49ers.