The orbito-sphenoids diverge only posteriorly, otherwise they are practically unpaired and form the median interorbital septum, which is very large in correlation with the extraordinary size of the eyeballs.
An teriorly and posteriorly separate ganglia have fused.
Close to this the small renal organ (i, mediad) and the larger renal organ (k, to the right and posteriorly) are seen, also the pericardium (1) and a coil of the intestine (int) embedded in the compact liver.
Stomatella, foot truncated posteriorly, an oper culum present, no epipodial tentacles.
Gena, foot elongated posteriorly, no operculum.
How would you define posteriorly? Add your definition here.