anacatadidymus

an·a·kat·a·did·y·mus

, anacatadidymus (an'ă-kat'ă-did'i-mŭs),

Conjoined twins united in the middle but separated above and below.

Synonym(s): dicephalus dipygus

[G. ana, up, + kata, down, + didymos, twin]