raphe

noun4

1. •
   A seamlike ridge or furrow on an organ, bodily tissue, or other structure, typically marking the line where two halves or sections fused in the embryo.

   • They are inserted into the midline raphae or the anococcygeal raphae and the coccyx. — 2004
2. •
   The connecting ridge between the two halves of the medulla oblongata or the tegmentum of the midbrain.
3. •
   The part of the stalk of an anatropous ovary that is united in growth to the outside covering and forms a ridge along the body of the ovule.

   • The vast majority of the raphes do not bifurcate (123 genera), but the raphes of 7 genera do. — 2003
4. •
   A longitudinal median groove in the valve of many diatoms.

   • The invariant occurrence of adhesive EPS at both the driving and the non-driving raphes supports a model for constitutive, rather than induced, secretion of the raphe adhesive. — 2007