Taxonomic key to the genus Raribius

1. Pharynx devoid of placoids ........................................................................................................................................ Raribius pawlowskii

– Pharynx with short rectangular placoids .................................................................................................................................................. 2

2. Internal bars I–III and posterior bars present ....................................................................................................... Raribius globuliferus

– Internal bars I–III and posterior bars absent ....................................................................................... Raribius minutissimus sp. nov.