816 DESCRIPTION OF PLATES. 



PLATE LXXIX. 



Fig. 1. Portion of shell of JW. macromphalus showing encrusting organisms in and near 

 the umbilicus. 



Fig. 2. Egg of Nautilus macromphalus, showing fenestrations and pectinations of the 

 outer capsule. There is a deep median notch extending from the front end through about 

 half the length of the capsule, x 1|. 



Fig. 2 a. Portion of one of the pectinate ridges of preceding. These ridges seem to 

 correspond with the annulations of the inf rabuccal tentacles (cf. fig. 6 a). 



Fig. 3. Same egg seen from the lower surface, showing the area of fixation. 



Fig. 4. Secretory products of the nidamental gland. The oval bodies are formed in 

 large bladder-like cysts. Zeiss 3 D, Cam. luc. Drawn from fresh object at Lifu, 9/2/97. 



Fig. 5. Infrabuccal apparatus of immature female (JV. pompilius). 



Fig. 6. Infrabuccal apparatus of mature female (iV. pompilius) with the subjacent portion 

 of the cephalopodium. 



o. Organ of Owen. 



v. Organ of Valenciennes. 



19. Nineteenth digital tentacle of the outer whorl. 



Fig. 6 a. Enlarged drawing of one of the infrabuccal tentacles of preceding. 

 Fig. 6 b. Apex of one of the infrabuccal tentacles of same. 



Fig. 7. Anterior portion of cephalopodium (N. pompilius 5 ) with hood partially bisected 

 and the flaps turned aside to show the inner whorl of tentacles embracing the buccal cone. 



f. Funnel. 



o. Organ of Valenciennes. 

 i.a. Infrabuccal apparatus. 

 e.l. Extrabuccal lobe. 



Fig. 8. Buccal cone of female in side view, with buccal membrane pressed back to expose 

 the jaws. 



i.m. Lower jaw. 



r. Teeth of radula. 



s.m. Upper jaw. 



i.a. Infrabuccal apparatus. 



p. Marginal papillae of buccal membrane. 



Fig. 9. Spadix of N. macromphalus (same as in PL LXXVIII. fig. 4) in frontal view. 



g. Glans. 



a. Sulcate tentacle. 

 6. Tessellate tentacle. 

 p.g. Preputial gland. 



Fig. 9 a. Portion of sulcate tentacle enlarged, showing glandular pits. 

 Fig. 9 b. Similar portion of tessellate tentacle, showing glandular crypts. 

 Fig. 10. Same spadix from left side. The maximum length of this spadix is 65 mm.; 

 the glans projects 28'5 mm. beyond its sheath; maximum width of glans, 25 mm. 



