Figure 2

Schematic overview of a retracted Hislopia malayensis zooid showing the main components of the polypide. The orifice at the distal end of the zooid reaches into the vesitbulum, which is separated from the proximally situated tentacle sheath by the diaphragm. Within the tentacle sheath the tentacle crown (i.e. the lophophore) is situated. The mouth opening is situated at the lophoral base and leads into the broad pharynx which is followed by an elongated, tube-like esophagus. The latter continues into the prominent proventriculus from where the digestive tract leads into the voluminous caecum. From the caecum the intestine leads into the anus, which terminates in the tentacle sheath.Abbreviations: a - anus, at - atrium, cae - caecum, cw - cystid wall, d - diaphragm, es - esophagus, int - intestine, lb - lophophore base, o - orifice, pv - proventriculus, t - tentacle, ts - tentacle sheath, v - vestibulum, vw - vestibular wall.