I wrote that tossup. My only regret was that--since I learned it from
the POV of a chemistry major, not a math major--I didn't look to see
if it had a different name in mathematics. [This is the sort of thing
that is always a risk when writing questions. I don't fault writers
for a lack of prescience; I do get annoyed, though, when experienced
writers don't even make cursory efforts to look up alternate answers
for questions that should obviously have them (e.g., "Waiting for
Godot").]
Also, space groups are, indeed, different from point groups, but they
*are* represented by Schoenflies and Hermann-Mauguin symbols. The
fact that the symbols listed are specific for point groups doesn't,
IMO, rule out space groups as an answer. The word "infinite,"
however, does, as there are an infinite number of point groups, but
not space groups.
--STI