I'm not sure if these are what you're talking about.  I hear them called gaiters or half-chaps.  I have a set of the basic black ones from Leather Legs and I love them. They zip down the back and have a leather snap-strap at the bottom.  They are very well made and contour to my boots well.  You just measure your legs and give the guy a call.

We wore canvas leggings in boot-camp that sound more like your definition but they wouldn't help much with riding - not like these do anyway.  He may be at the ROT Rally in Austin right now though.  Wish I was too.

Check with REI. Mountaineering gaiters work pretty well. But, they are nylon nowadays... I'm afraid old style canvas may be do it yourself. My wife's grandfather was a Memphis TN motor officer in the 1920s and 30s...rode a Henderson. Pictures of him showed that MPD used cavalry boots or gaiters as described.
-WD

THATS EXACTLY THEM!!  I remember polishing them every other day for years and years as a kid.

Expensive maybe, but they would last you forever.  They will allow you to wear a shorter shoe/boot while still protecting your calf from hot exhausts, road debris, loose chains, etc..

The Leather Legs work really well too.  They definitely protect your legs from bouncing road crap.  They're hand-made and mine look like they'll last a lifetime too.  It's mostly a difference in style and price.  I've gotta admit the puttees look cool though.

the Brazos River i grew up in fort bend county texas
i have not herd that name in almost 10 years

shawn