Scanning Electron Microscopy (SEM) and stacked light microscopy images of representative specimens of A. brunnea: A, B DANA_3929VIII C SN105_08, A. vanderspoeli: D–E DANA_3558VII (Holotype, NHMD-232132) F KH1110_15 and A. turriculata: G, H DANA_3929VIII I SN105_19. Apical angle is the most useful morphological feature for distinguishing between the species (B–C, E–F, H–I). The shell of A. brunnea is always brown (C); however, the colour of A. vanderspoeli and A. turriculata shell and soft tissues (F, I) can vary and these are not reliable features for identification.