Farther posteriorly, a large outpocketing
of the ventral wall of the foregut, which curved to the right side of the foregut, was the prospective radular sac (Fig.
Winter and spring macroinvertebrate drift in an outpocketing
of the lower Mississippi River, Louisiana (USA).
while others describe it as an outpocketing
of the ectodermal rhynchodeum (reviewed in Friedrich.
The tentacle apparatus is composed of an ectodermal component that invaginates to meet an outpocketing
of the endoderm.
Like teredinids, xylophagainids bore into woody substrates, ingest the excavated wood particles, and store them in a specialized caecum formed by an outpocketing
of the stomach (Purchon, 1941; Turner, 1973).