[ ā-krā′nē-ə, ə-krā′- ]
Congenital absence of all or a part of the skull.
Related formsa•cra′ni•al adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Examples from the Web for acrania
The skull-less animal lancelet, which is still living, affords a faint idea of the members of this group (acrania).Was Man Created?|Henry A. Mott
Hence we may call it after the Acrania as well as after the Tangles.The History of Creation, Vol. II (of 2)|Ernst Haeckel
It is absent as a distinct gland in the Acrania and Cyclostomata.