1	Articulation of heterogomph chaetae with boss extraordinarily expanded; antennae minute	Namalycastis fauveli
–	Articulation of heterogomph chaetae with boss not extraordinarily expanded (equal or little longer); antennae extending beyond tip of prostomium	2
2	Notochaetae present in all or several parapodia; antennae distally pointed	3
–	Notochaetae absent in all parapodia; antennae distally sub-acute	Namalycastis jaya sp. n.
3	Anterior and posterior eyes more or less same size	4
–	Anterior eyes substantially smaller than posterior ones	Namalycastis glasbyi
4	Lengthy posterodorsal tentacular cirri reaching back to chaetiger 5–6 and tripartite pygidium	Namalycastis indica
–	Postero-dorsal tentacular cirri only reaching back to chaetiger 2–5; multi-incised pygidium	Namalycastis abiuma species group