PLATE XL 



Work of Xyloterus bivittatus, and Phloeotribus picea Mopk. MS. 



a, Work of the wood-mining beetle, Xyloterus byvittatus, in the sapwood of 



spruce— natural size. 



b, Fungus {Polyporus volvatus) growing from mines of Xyloterus bivittatus on 



the surface of the wood after the bark had been removed— natural size. 



c, Work of Phloeotribus pieea Hopk. MS. in spruce. 



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