Sagartiogeton erythraios internal anatomy
A, longitudinal section through distal column, showing mesogleal marginal sphincter;
B, cross-section of the directive mesenteries attached to the siphonoglyph (arrow), showing diffuse retractor muscles;
C, cross-section through a tentacle showing longitudinal ectodermal muscles;
D, cross-section of the pedal disc showing basilar muscles;
E, cross-section of the mesenteries proximally, showing differentiated parietobasilar muscles differentiated (arrow).
Scale bars: A, B, 1 mm; C, D, 0.1 mm; E, 1 mm