The slides of cocci and bacilli aren't very good. It might be a good idea for the TA to make a set of slides on their own.  Links from webpages can also be found and printed off.  Notice how certain evolutionary achievements, such as the evolution of chlorophyll, can be traced from the blue-green bacteria to the green algae, and how green algae have developed additional accessory photosynthetic pigments (carotenoids and xanthophylls).  If live material is available, demonstrate the color difference in the blue-greens and the greens.  Students have been confused in previous years about the prochloro bacteria.  The TA might want to check the textbooks up front to see if there is a better description.  These are bacteria that are believed to have evolved into chloroplasts.  They differ from the blue-green algae in their color and accessory pigments and are very similar to chloroplasts in many ways.  For live material, I usually grabbed some lichen off a tree.  The large flip-chart in the room has bacteria on it as well as some green algae.  I saved the last three of the green algae for the next lab, as there are many names and identities to remember in this lab.  Links are available on the main page.