The septum nasi is removed, but the mucous membrane on the turbinal
bones is retained. _a_, _a′_, Superior turbinal bone, dotted line
indicating limit between anterior coiled part and posterior uncoiled
part; _b_, _b′_, superior turbinal folds, inclosing bars of
cartilage; _c_, fold of mucous membrane formed by union of _b_ and
_b′_; _d_, _d′_, anterior coiled and posterior uncoiled part of
inferior turbinal, dotted line indicating septum between them; _e_,
_f_, inferior turbinal folds, former (alar fold) inclosing bar of
cartilage; _g_, _h_, _i_, superior, middle, inferior meatus; _o_,
_o′_, frontal sinus; partial septum between _o_ and _o′_; _q_, nasal
part of frontal sinus (nasal sinus); _r_, lateral mass of ethmoid
bone; _s_, sphenoidal sinus; _t_, cranial cavity; _u_, opening made
in superior turbinal bone at point where drainage of frontal sinus
may be obtained. (After Ellenberger, in Leisering’s Atlas.)
]