Fig. 5

Gigantopelta chessoia, photographs from dissection of adult specimens. a. Inside face of the right-posterior part of the mantle with gonad ‘flap’ removed to reveal the gonopore. b. A section of the right-posterior mantle wall showing the gonad ‘flap’ and anus. Arrowhead indicates the gonad ‘flap’ opening. c. Transverse section through a female, showing relative positions of ovary and nephridium. d. Transverse section through a male, showing stomach and digestive gland. e. Close-up of granular crystalline material (arrowhead) within the oesophageal gland. f. Posterior view with the pericardium removed to reveal the auricle and the ventricle. g. Transverse section through the ctenidium showing the large blood sinuses underneath. h. Transverse section through the mantle roof showing large blood vessel (arrowhead). i. Sagittal section through the ventricle, with blood clot removed to show muscle bundles. j. Sagittal section through the auricle. Abbreviations: a, auricle; an, anus; hp, hypobranchial gland; ct, ctenidium; dg, digestive gland; gf, gonad ‘flap’; gp, gonopore; i, intestine; ne, nephridium; pe, pericardium; og, oesophageal gland; ov, ovary; s, stomach; si, blood sinus; te, testis; v, ventricle. Scale bars of a–b, e, i–j: 1 mm; f–g, h: 5 mm; c–d: 2 mm