Explanation of Names
From Latin crena, a notch.
crenate, crenulate, adjective - furnished with small blunt teeth, which take the form of segments of small circles (Jardine). Crenulate refers to smaller, more even, perhaps tooth-like, projections (Gordh and Headrick).
Gordh and Headrick, pp. 241-242 (1)
Jardine, entry for crenate, crenulate (2)