Reference for Chullin 248:19

בנבלתם ולא בעור שיש עליו ב' חצאי זיתים

convey uncleanness, as stated in the latter part [of the Mishnah]: R'AKIBA, HOWEVER, AGREES THAT IF THERE WERE TWO PIECES OF FLESH.

Jastrow

Jastrow

Jastrow