holoacrania

hol·o·a·cra·ni·a

(hol'ō-ă-krā'nē-ă),
A congenital cranium defect in which bones of the vault are absent.
[holo- + G. a- priv. + kranion, skull]
References in periodicals archive ?
[2] Anencephaly is classically subdivided into two forms: holo-anencephaly (complete absence of forebrain and cranium) and mero-anencephaly, in which "the cranium and the brain are present in rudimentary form." [3] Others employ the related terms "holoacrania" and "meroacrania," referring to the degree of bone absence.