I made a few soapstone pipes years ago. There were some "elbow" pipes made of clay by eastern natives that did not have a separate stem, but these had an elongated tube which served as a stem. There were tubular pipes of stone and of bone that had no stem, but as short as this pipe is, I would think it would need a stem of some sort. Typically, these would be inserted into the horizontal extension of the stone pipe, but the diameter of the hole for inserting the wood or cane stem would usually be in the neighborhood of 3/8" to 1/2", and the hole in that pipe looks too small. I'm not sure what to make of the little "batwings" on either side of the mouth or stem hole, either. Hard to know what he was thinking. Does this pipe show evidence of having been used?
Notchy Bob