What is "stomochord"

n. (context biology English) A buccal diverticulum in the proboscis of hemichordates

The stomochord is a flexible, hollow tube found in hemichordates. Stomochords arise in embryonic development as an outpocketing from the roof of the embryonic gut anterior to the pharynx. In adults, they extend dorsally from the pharynx into the proboscis, and serve to communicate with the oral cavity. Their walls are composed primarily of epithelial cells, but ciliated and glandular cells are also present.