Endoturbinate

The endoturbinates or endoturbinate volutes (Endoturbinalia) are a group of turbinates, as the ectoturbinates.

They are the ones that come forward medially, to the neighbourhood of the perpendicular plate; they are the only one visible on a head sawn longitudinally from the middle and seen from the medial side.

The first one, the dorsalmost, is always significantly bigger than all the others: it is the great volute. that comes forward more or less inside the bose cavity between the dorsal and the ventral concha. It is therefore walled the middle concha (Concha nasalis media). This volute also has the particularity of not beeing so entirely wraped on itself as the others; it presents on the contrary a bullous disposition, with a definite cavity (Sinus of the first endoturbinate) that opens by an orifice in the nasal cavity or the maxillary sinus, according to the species.

If we only consider as true volutes the formations housed within the papery sheet and inserted by their basis to the cribriform plate, we see that the great volute is indeed the first. Nonetheless, most authors consider it as the second and tie up the dorsal nasal concha to the row of the endoturbinates of which it then represents the first one. If we take into account that this concha grows in most species by an idependant ossification center and connects itself to the dorsal part of the papery sheet without being contained in its cavity, we will agree that it can in no way be assimilated to a true volute.