Getting Keyboard to work with musescore

A Newbie question! I have been learning Musescore and I have a Key Studio 49 note USB keyboard with an iMac. I can get the keyboard to work with Garage Band but can't seem to get Musescore to recognize it. The enable sound while editing and the enable midi icons are checked. I have also attached a screen shot of the i/0 preferences. I would love some guidance to get this going. Thanks. Jeff