Desmograptus micronematodes Spencer, from the lower dendroid bed at Thornton quarry, Cook Co., Illinois, USA (middle Wenlock or lundgreni Biozone) is remarkably preserved in relief, outlined in pyrite. The internal details of the thecae, and of the stolon system, examined using the SEM, enabled us to reconstruct the growth of a stipe. Autothecae have a proximal portion, the stolotheca, partially within the parent autotheca, containing a stolon£ a central portion which has a branching node of the stolon succeeded by the internal portions of its daughter autotheca and bitheca£ and a distal portion which is an open cup. The stolons and stolonal nodes are formed of a dense crassal fabric, and are surrounded by a loose fabric of three-dimensional fibrils. The nodes have a complex structure of three boxes with proximal and distal nozzles. The base of a bitheca, and the base of each autothecal cup, has a central nozzle surrounded by a unique honeycomb fabric. Cortical and fusellar fibrils bear a surface structure of spiral ridges.