Assertion: trumpeter swan's bill | /r/HasProperty | concave
Facets:
value: deeply
type: DEGREE
value: with a medial prominent line
type: OTHER
Source sentences:
text: Bill along the ridge 4 1/4 inches, from the angle of the eye to the tip 4 10/12; lower mandible along the edge 3 1/2; depth of bill at the angle of the mouth 1 9/12, its breadth at the nostrils 1 4/12, near the end the roof of the mouth is deeply concave, with a medial prominent line, on which is a series of hard tubercles.