Table 2

1) All mesenteries perfect

a) Siphonoglyph separated from the actinopharynx, with a conchula; 8 pairs of mesenteries, all perfect

aa) Siphonoglyph without conchula, not separated from the actinopharynx

b) Column divisible into regions. Arrangement of tentacles regular but atypical with 7 in the inner cycle. A weak, diffuse sphincter

bb) Column not divisible into regions. No sphincter. Tentacles hexamerously arranged

2) Mesenteries not all perfect

c) Siphonoglyph with a conchula, rarely completely separated from the actinopharynx. Second cycle formed by only 4 pairs of imperfect and sterile mesenteries (2 ventral and 2 ventrolateral pairs)

cc) Conchula absent. Second cycle formed by 6 pairs of imperfect and fertile mesenteries. Well developed parapet and fosse present