The pictures below show the standard "10-20" system names for the EEG caps that are currently used in the MEG lab. This would be helpful in order to have a reference of where a channel number (1-74) is in terms of the 10-20 system. Since the MEG lab has two types of caps, the old blue ones and the newer white ones, there are two images below showing the channel names for both:
Old EEG Caps
New EEG Caps
Note that the difference between the naming/numbering of the two caps is that in the old caps have channels FP1 and FP2 as numbers #1 and #3 respectively, whereas in the new caps channels FP1 and FP2 have been knocked off and instead PO9 is #1 and PO10 is #3.