Two resin casts of the burrows of the thalassinidean decapodLepidophthalmus louisianensis were madein situ on a tidal flat at Dauphin Island, Alabama. The following burrow sections can be recognised: an upper narrow shaft leading from the surface to a depth between 17 and 28 cm; a main wider shaft with several chambers leading to a depth of more than 1 m; short horizontal tunnels branching off the main shafts at several depths. The burrow wall has a thick lining in all parts except on bottoms of the horizontal tunnels and has a higher organic content than the ambient sediment.