1. Colonies membranous and/or lobate........................................................................................................... 2
-. Colonies digitiform or digitate..................................................................................................................... 5
2. Interior base with sparsely ornamented rods............................................. A. sollasi Wright & Studer, 1889
-. Interior base without sparsely ornamented rods.......................................................................................... 3
3. Only capstans and spindles in coenenchyme.................................................. A. grandis Casas et al., 1997
-. Coenenchyme also with clubs.................................................................................................................... 4
4. Capstans very tuberculate, tentacle bases with clubs............................................................ A. roseum n. sp
-. Capstans sparsely tuberculate, tentacle bases without clubs........... A. antarcticum Wright & Studer, 1889
5. Interior with spindles only...................................................................... A. haddoni Wright & Studer, 1889
-. Interior with rods and spindles.................................................................................................................... 6
6. Colonies with slender lobes (<0.5 cm wide)......................................................................... A. jorgei n. sp.
-. Colonies with robust lobes (1 cm wide and more)...................................................................................... 7
7. Interior of complete colony with sparsely ornamented rods, most clubs without central wart......................................................................................................................................................... A. glaciophilum n. sp.
-. Only interior of base with sparsely ornamented rods, most clubs with central wart......... A. yepayek n. sp.