There is no real standard for the name that will be associated with a USB based serial device. Typically, though, the device name will match /dev/tty.* including the period literally. So in MATLAB, try
and see if you find anything.
The default Mac serial ports have names that match /dev/tty[p-w][0-9a-f] . Also, you will probably see /dev/tty.Bluetooth-Incoming-Port which will not have anything to do with USB.