A Entomobrya atrocincta. SEM photograph of mouth cone, four labral papillae with multiple projections (1) (arrow points to 3rd papilla from left to right) and labial appendage (2) B–D drawings of labral papillae of Entomobrya and Willowsia species: Entomobrya with multiple projections per papilla (column B); Entomobrya with a single projection per papillae (column C); labral papillae of all Willowsia species occurring in the Eastern United Sates (column D). Note Willowsia n. sp. 1 can be differentiated by the presence of multiple projections per papilla. E. jubata sp. n. and E. ligata are not included in figure but are similar to E. clitellaria and E. unifasciata sp. n. respectively. Scale bars = 20 µm.