[Taxacom] U-shaped channel label

[John Grehan]

Colleagues,

I am describing some morphological structures that include the presence a
short U-shaped channel. Does anyone know of a technical or geometric term,
whether from botany or zoology, that might be applied to this formation. I
prefer to have a label other than the long winded 'u-shaped channel' but I
will use that if there is nothing better.

John Grehan