Add-ins for FireFox, Chrome, and IE that allow you to bulk download multiple files linked to on a single page come and go for some reason. Currently Simple Mass Downloader for Chrome is available and does the trick quite well.
After the add-in is installed, a small icon with a blue down arrow will appear. You can also activate this utility by right clicking on any web page and selecting, 'Add page links to list'.
Simple Mass Downloader will open as a separate window. Simply check off the files you need to download. It includes an array of options.
Be sure that you have selected a folder to download the files to in advanced settings in Chrome and have the 'Ask where to save each file before downloading' option deselected.