Imprints of the surface coat (glycocalyx) from the cuticles of living second stage dauer larvae (DL2) of Anguina agrostis (syn. A. funesta) have been examined using incident light fluorescence microscopy and scanning electron microscopy. These surface coats contain residues of N-acetyl-D-glucosamine which were detected by treatment with wheat germ agglutinin labelled with either fluorescein or rhodamine. They also contain protein which was demonstrated by treatment with either pepsin or trypsin. These enzymes inhibited the attachment of the coryneform bacterium Clavibacter sp. to the surface coat, indicating that proteins play a crucial role in the adhesion of these bacteria to the nematode. This inhibition of attachment was reversed within 18 h after removal of the DL2 from the enzymes, indicating that the nematode was capable of renewing its surface proteins.