It's horribly drawn in a non-standard convention so it's a bit confusing.
It's a standard two-way series crossover, but with the super-tweeter and tweeter wired in series in the "tweeter" location. The tweeter then shunted by the 10uF capacitor to low-pass it.
Also, I wouldn't necessarily assume this diagram is accurate, since it originates from "Peter Gunn."
When the Magnepan folks make an official crossover diagram available then we'll know for sure.
Cheers,
Dave.
