archaeostomatous

Century Dictionary and Cyclopedia

1. Pertaining to or having the characters of the Archæostomata.
2. In biology, having a primitive blastopore or original orifice of invagination of a blastosphere which has undergone gastrulation; retaining an archenteric aperture, as distinguished from any other which may be acquired by a deuterostomatous gastrula: it is the usual state of those gastrulæ which are formed by emboly.

Wiktionary

1. adj. biology Applied to a gastrula when the blastopore does not entirely open up.

GNU Webster's 1913

1. adj. (Biol.) Applied to a gastrula when the blastopore does not entirely close up.