Lost storage space on my mac

Today, I tried to install Windows 10 through Boot Camp on my MacBook Pro (Retina, Mid 2012), OS X El Capitan Version 10.11.1 with 250 GB SSD. I had around 80 GB free and I gave 40 GB for Windows and 40 GB for the mac. I got to the step within Bootcamp where it was partitioning my SSD, and I went away for a few minutes. When I came back my Macbook had restarted. I opened Disk Utility and saw that under APPLE SSD SM256E Media it says 251 GB but under Macintosh HD only 209.79 GB capacity with 47.91 GB free. It appeared to have partitioned but it hasn't and therefore I have lost some storage space.

If it hasn't partitioned, where are the missing GBs? Why is the capacity only 209.79 GB? Please, help me. Thank you!