The Collaborative International Dictionary
Archencephala
Archencephala \Ar`chen*ceph"a*la\, n. pl. [NL., fr. Gr. pref. ?
+ ? the brain.] (Zo["o]l.)
The division that includes man alone.
--R. Owen.
Wiktionary
archencephala
n. (plural of archencephalon English)