HC-3 channel orders

Hello,

I am facing trouble in understanding the arrangement of channels in hc-3 data sets.
While using the matlab scripts of hc-2 dataset for hc-3, to convert .eeg files to .mat files, I am getting number of channels like 65 (ec013), 78(ec016) etc.
I am unable to relate that with the hc3-epos file. (eg ec013 files have 8 electrodes, 4 in EC and 4 in CA1/DG/CA3. How should I relate that to the 65? And do the first 8 matlab channels correspond to the 8 recording sites of first electrode (shank), the next 8 to the second one and so on?)

It would be great if I could get help regarding how the electrodes/channels have been organized, so that I can analyze the data.

Bijurika