it looks like a transitional piece, before squat sodas but after the Midwestern ribbed flasks. it has that chestnut flask lookin top on it. maybe 1830s? it looks like it used a 3 piece ricketts mold. I could be way off though. just my observation. looks like this one, courtesy of http://www.sha.org/bottle/beer.htm#Early Porter & Ale Bottles.
Hey Cliff nice piece of glass there. Were about was it dug . I thought IP tended to be later 1840 but more to the 50s .Not that I know. Be nice to be able to tie it to some were along the river. Hope you and Sod and the other guys are doing well.Bill
The inverted taper is similar to alot of early Pittsburgh sodas but the glass appears much thinner than most sodas, it also appears larger than a soda. Here is a pic from Tod's site . . . http://www.sodasandbeers.com