The infrared spectra of a number of N-substituted glycosylamines have been examined over the ranges 1800–1500 and 960–700 cm.–1; the spectra indicate the presence of a pyranose ring. Comparison of the spectra of the two isomeric N-phenyl-D-ribosylamines with those of methyl β-D-ribopyranoside and methyl and benzyl β-D-ribofuranoside, suggests that the ribosylamines are pyranose but a furanose structure cannot be entirely excluded here because of the large number of peaks present in the spectra. There is no spectroscopic evidence for an earlier suggestion that some of the glycosylamines have an acyclic structure. A number of new glycosylamines are described.