raphe
/ˈreɪfɪ/noun
(pl. raphae /-fiː/)
1- Anatomy & Biology a groove, ridge, or seam in an organ or tissue, typically marking the line where two halves fused in the embryo, in particular【剖, 生】（器官或组织的）缝（际）, 尤指：
1.1
- the connecting ridge between the two halves of the medulla oblongata or the tegmentum of the midbrain延髓缝, 中脑盖正中线。
1.2
- Botany a longitudinal ridge on the side of certain ovules or seeds【植】种脊; 珠脊。
1.3
- Botany a longitudinal groove in the valve of many diatoms【植】（硅藻）壳缝。
词源
mid 18th cent.: modern Latin, from Greek rhaphē 'seam'.