How Can I See Com Port for USB Device on Macbook Pro

I'm trying to connect an arduino to my macbook pro and wanted to see which communication port I'm connected to. I didn't see anything in System Information to help me identify com ports thru USB connections. Please help. Thanks

MacBook Pro with Retina display, OS X Yosemite (10.10.4)

You want to see a communications port from what application ? Most applications that use communication ports, or know as tty ports will provide a way to list then for you to make a selection.

You can go into terminal and just type

ls /dev/tty*

and look at your results for a ttyUSBxx or more likely tty.USBxx device, where xx is the sequence number.