1 Gubernaculum absent. Cuticle looks smooth. Cephalic and cervical setae 7–8 µm long............................................................................................... A. megastoma Timm 1961
Gubernaculum present. Cuticle distinctly annulated. Cephalic and cervical setae less than 4 µm long.............................................................................................................. 2
2 Distal tips of spicules blunt ....................................................... A. unita Lorenzen 1977
Distal tips of spicules pointed ......................................................... A. bullacauda sp. n.