Our correspondent Mr. J. D. Pasteur is such a passionate naturalist, that he had no rest before he procured a nest of the black-tailed, red Tree-Rat. A specimen of the kind has been presented by that gentleman to our Museum and is at present exhibited in a glass case. This globulous nest has a diameter of 18 cm., the entrance, placed sideways, a diameter of about 6 cm. It has nicely been constructed of small branches with leaflets and parts of large leaves.