DESCRIPTION OF PLATES LXXV— LXXXIII. 



PLATE LXXV. 



Nautilus macrompJialus, cj . View of pallio- visceral region from below with the organs 

 showing through by transparency. 



Sketched from the fresh object, with natural colours, at Lifu, October 26th, 1896. 



Each renal sac contains a bilobate renal follicle surrounded by the scarlet concretionary 

 substance. The liver has a dark purple colour. 



PLATE LXXVI. 



Fig. 1. N. pompilius, $ . Ventral view with reflected mantle, showing natural colours. 



f.o. Funnel-organ. 



a.i. Ala infundibuli. 



x. Ligamentous limbus passing from funnel-organ over the surface of s.m. the shell-muscle. 



m.e. Mantle-edge. 

 $ Vulva. 



br. 1 and br. 2. Branchiae. 



osph. 1 and osph. 2. The osphradia. 



nid. Nidamental gland. 



v.p.o. Viscero-pericardial orifice. 



b. Bristle passed into the opening of the duct of the pyriform gland. 



a. Anus. 



ac. Accessory nidamental gland. 



The renal orifices occur (when the mantle is reflected) in front of the bases of the 

 branchio-cardiac (efferent branchial) vessels. 



Fig. 2. Renal concretions ; the upper figure shows the concentric stratification under high 

 magnification. 



Fig. 3. Harpa sp. from Lifu seen from below to show the divisions of the foot, the 

 semilunar propodium with sulcate border, the mesopodium and the me.tapodiurn. (Cf. text in 

 explanation.) Natural size. 



Figg. 4 and 5. Haliotis sp. from New Britain. Anterior end of animal with shell 

 removed, seen in ventral and dorsal view to illustrate the bilaminate, tentaculiferous epipodium 

 (ep.) which is produced in front into a lobe which overlies the proboscis (buccal cone). 



m. Mouth. 



f. Platypodium (foot). 



e. Eye-stalk. 



106—2 



