Dictionary.net

• Muscles stretching from the ventral valve to the cardinal process, and by their contraction opening the shell.

1920 - A dictionary of scientific terms.
By Henderson, I. F.; Henderson, W. D.

• [Latin] Muscles stretching from ventral valve to cardinal process, in brachiopods; muscles in avicularia.

1920 - A dictionary of scientific terms (6th edition)
By J.H. Kenneth