I'll have to ask the butcher next time I'm there. I've never seen any out at the grocery store where I shop (which is a block away from my house). I'll keep the "soup bones" terminology in my back pocket too. I didn't know what else a marrow bone was called
Also, I didn't realize the corn starch bone was different then the edible nylabones. Are those the ones that look just like the plastic nylabones, but are edible? Those I haven't tried yet so I'd have to take back my comments as I might have had the two confused
