Here is the part I am referring to:

Mercury is the deity whom they chiefly worship, and on certain days they deem it right to sacrifice to him even with human victims. Hercules and Mars they appease with more lawful offerings. Some of the Suevi also sacrifice to Isis. Of the occasion and origin of this foreign rite I have discovered nothing, but that the image, which is fashioned like a light galley, indicates an imported worship. The Germans, however, do not consider it consistent with the grandeur of celestial beings to confine the gods within walls, or to liken them to the form of any human countenance. They consecrate woods and groves, and they apply the names of deities to the abstraction which they see only in spiritual worship.

I know that there is little information on the West Germanic pantheon, but any information on any of the referenced gods and to what Germanic pagan gods they are referring to would be great.