Dictionary.net

• A genus of paracephalous monsters, without any neck-a slight depression indicating the limits of the head and body.-I. G. St. Hilaire.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison

• A monster having a large but badly shaped head and with only the face distinct, with rudimentary sensory organs and no thoracic members. [Gr.]

1916 - Appleton's medical dictionary
By Smith Ely Jelliffe