Smith.] 274 [February 3, Mr. F. G. Sanborn exhibited a branch of white oak, Q. alba Linn., from Avhich the extremity had been severed by the larva of Elaphidion villosicm Fabr., and which had been also perforated by the larva of Leptostylus macula Say. Tlie specimen illustrated in a striking manner a degi'ee of intelli-gence displayed by the first mentioned species, which after completing its central burrow, and nearly severing the twig, as usual, between its winter quarters and the body of the tree, found its operations in-truded upon by the larva of Leptostylus, which was engaged in pene-trating the twig in the same direction, but nearer the bark than the burrow of Elaphidion. He maintained that the specimen showed incontestably that on making this discovery, the larva of ElapJtidion had retired in its burrow about one half inch from this point, and successfully imdertaken the by no means inconsiderable labor of sev-ering the twig a second time in a locality sufficiently removed from the encroachments of Leptostylus to satisfy its somewhat misentomical feelings. February 3, 1869. Dr. Charles Pickering in the chair. Sixteen members present. The following papers were read : — Notes on iSTew or little known Species op American Can-croid Crustacea. By Sidney I. Smith. The following notes were begun as part of a more extended article on the higher Crustacea of the western coast of tropical America, but the delay in bringing together the requisite matei'ial and the discov-ery of undcscribed forms from the eastern coast, have induced me to publish in this preliminary manner the more interesting of the new or little known species of both coasts. The materials upon which the descriptions are based, unless otherwise indicated, are in the collec-tions of the ]Nbiseuin of Yale College. Xantho denticulata White, List of Crust, in British Mus., p. 17 (no description), 1847.