What constellations touch the 9-degree wide Zodiac? Say Barry, could you abuse the answer-your-own-question feature of
this site, and answer the following question:

As noted in How many constellations in the Zodiac? the
ecliptic itself touches 13 constellations, but the Encylopedia
Brittanica defines the Zodiac as "a belt around the heavens extending
9 [degrees] on either side of the ecliptic":

http://www.britannica.com/topic/zodiac

The Old Farmer's Almanac for 2014 (and previous years) notes (page
114) that Moon occasionally crosses into 5 "non-Zodiac" constellations
at times:



So, exactly which constellations are "in the Zodiac" if the Zodiac
extends 9 degrees on either side of the ecliptic?

And why 9 degrees? I know Venus can be as much as 8.25 degrees from
the ecliptic,
While I can't answer the 9 degrees part, 
http://www.space.com/5417-ecliptic-zodiac-work.html notes, the band of 
the zodiac actually passes through 22 constellations: 

 
In fact, as pointed out by the well-known astronomical calculator, 
Jean Meeus, along with Ophiuchus, there are nine other constellations 
that occasionally can be visited by the Moon and planets: Auriga, the 
Charioteer; Cetus, the Whale; Corvus, the Crow; Crater, the Cup; 
Hydra, the Water Snake; Orion, the Hunter; Pegasus, the Flying Horse; 
Scutum, the Shield; and Sextans, the Sextant.



So in truth, there really aren't twelve zodiacal constellations, but 
twenty-two!