Is the media grid class gone from Twitter bootstrap?

I'm trying to use the media grid class and its just showing up as an unordered list. I did a search in the bootstrap.css and can't find media-grid. Or is there a new method to achieve the media grid look? Thanks ``` <!--Media grid--> <ul class="media-grid"> <li> <a href="#"> <img src="http://placehold.it/290x200" /> </a> </li> <li> <a href="#"> <img src="http://placehold.it/290x200" /> </a> </li> <li> <a href="#"> <img src="http://placehold.it/290x200" /> </a> </li> <!--media grid--> ```