Check your fridges to see if you purchased Dole Hearts of Romaine Bagged Salad.  They have been voluntarily recalled.  Here is some more information:

The product being recalled is Dole Hearts of Romaine coded 0540N165112A or B, with Use-by date of June 26 and UPC 7143000956 due to a possible health risk from Listeria monocytogenes. Dole Fresh Vegetables is coordinating closely with regulatory officials. No illnesses have been reported in association with the recall.

The product code and Use-by date are in the upper right-hand corner of the package; the UPC code is on the back of the package, below the barcode. The salads were distributed in nine U.S. states (Alabama, Florida, Georgia, Maryland, North Carolina, Pennsylvania, South Carolina, Tennessee and Virginia).

Read more on the recall.