BUCCINUM. 



361 



PAGE. 



Nerve centres anterior 318 



pallial 323, 324 



pedal 319 



penis 319 



of proboscis and proboscis 



sheath 321 



visceral 325 



endings in osphradium 332,333 



Nervous system 317 



Nephridium 335 



Nephridial gland 339 



Nephridio- cardiac vein 310, 316 



Odontoblasts 304 



Odontophore 283, 295 



bands 296 



cartilage 297 



histology 302 



muscles 296 



mode of action ... 299 



Oesophagus 283,290 



caecum 285, 292 



epithelium 291 



Operculum 256, 265 



Optic vesicle 326 



Osphradium 270, 329 



leaflets 330 



nerve endings 332, 333 



Otocysts 320, 334 



Ovary 345 



Pallial arter}' 311 



cavity 269 



complex 269 



circulation 316 



nerves 323, 324 



siphon 270 



Parasites 359 



Patella 307, 341 



Pectinibranchia 254 



Pedal ganglia 319 



gland 262, 268 



groove 256, 267 



Penis 342 



nerve 319 



Periostracum 258, 259 



secretion of 261 



Pharynx 282, 287 



Pleural ganglia 321 



Pleurekbolic 282 



Pleurembolic 282 



Proboscis 280 



Prosobranchia 254 



PAGE. 



Radular teeth 301 



variation in teeth 301 



formation and growth 304, 305 



Rectum 287 



glands 287 



Renal aperture 271, 287 



organ 335 



blood supply 315 



principal system... 338 

 secondary lamellae 338 



sinus system 314, 315 



Reno-mucous vessel ... 309, 314, 316 



Reno -pericardial aperture 336 



Reproductive organs 341 



Rhynchodaeum 282 



Rhynchostome 282 



Salivary ducts 284, 290 



glands 283, 290 



Sense organs 325 



Shell 256 



formation 261 



layers 259 



sinistral 257 



siphon 258 



sutures 257, 258 



structure 260 



Silica in teeth 307 



Spermatozoa 343 



Stiftchen 328 



Stomach 285, 292 



Streptoneura def 253, 254 



Streptoneurous twisting 317 



Tentacles 255 



supernumerar}' 255 



Tentacular arter}^ 313 



nerve 320 



Testis 341 



" Triangle lateral " 339 



Vaginal oviduct 345 



Vascular system 307 



Venous system 313 



Ventricle 310,311 



Visceral aorta 311, 313 



commissure 317, 318, 323 



ganglia 324 



mass 255 



nerves 326 



Whorl 257 



