a. (Zoöl.) Having a head; -- said of most Mollusca; -- opposed to
a. (Zool.) Pertaining to, or characteristic of, the Lyencephala. [ 1913 Webster ]
[ Micr- + Gr. &unr_; brain. ] Having a small brain. [ 1913 Webster ]
a. (Zool.) Of or pertaining to the Myelencephala. [ 1913 Webster ]