tviii GENERAL INDEX. 



Page Sec. 



Mode of copulation 527 . 1390 



Internal generative viscera 527 . 1391 



" Sac of the dart ".. . .........!.... 527 . 1391 



Male generative system .......... ..f "J - . ; \ 528 . 1392 



Testicle ..*;-.... 528 . 1393 



Vas deferens ....:. 528 . 1393 



Intromittent apparatus 528 . 1393 



Female generative system 528 . 1394 



Ovary 528 . 1395 



Oviduct and "uterus" 528 . 1395 



Spermatheca 528 . 1396 



Multifid vesicles 529 . 1397 



Nervous system 529 . 1393 



Senses 529 . 1399 



Structure of the cephalic tentacula 529 . 1400 



Peculiar arrangement of tentacular nerves 530 . 1401 



Distribution of the GASTEROPODA into orders 530 . 1402 



PULMOBRANCHIATA 531 . 1403 



Branchiae of marine Gasteropoda 531 . 1404 



NUDIBRANCHIATA 532 . 1406 



INPEROBRANCHIATA 532 ." 1407 



TECTIBRANCHIATA 532 . 1408 



PECTINIBRANCHIATA 532 . 1409 



TUBULIBRANCHIATA 533 . 1411 



SCUTIBRANCHIATA , 533 . 1412 



CYCLOBRANCHIATA 533 . 1413 



HETEROPODA 534 . 1414 



Circulating system of the GASTEROPODA 534 . 1415 



of Buccinum 534 . 1415 



Tritonia 535 . 1416 



Doris 535 . 1416 



Aplysia 535 . 1417 



Structure of the venous system of Aplysia 535 . 1417 



No proper absorbent system exists in the Mollusca 536 . 1418 



Structure of the heart in Aplysia 536 . 1419 



Lacunar system of the Gasteropoda 536 . 1420 



Milne-Edwards' s discoveries relative to the circulation in the 



Mollusca 537 . 1421 



Prof. Huxley's observations relative to the circulation in Firola . 537 . 1422 



Nature of the circulation in Haliotis 538 . 1423 



Patella 540 . 1428 



Structure of the heart in Chiton, Haliotis, Fissuretta, &c. . . . 541 . 1430 



Respiratory and circulatory organs of Pterotrachea 541 . 1431 



" Water-vascular system " of the Gasteropoda 541 . 1432 



Digestive system 541 . 1433 



Varieties in the structure of the mouth 542 . 1434 



Mouth of Pleurobranchus 542 . 1435 



Tritonia Hombergii 542 . 1436 



PECTINIBRANCHIATA 542 . 1439 



Proboscis of Buccinum 543 . 1440 



Alimentary apparatus of Buccinum 544 . 1446 



Salivary glands 544 . 1447 



Alimentary apparatus of HETEROPODA 544 . 1449 



Structure of gizzard in Scyllaa 545 . 1450 



Aplysia 545 . 1450 



Hepatic system of the Gasteropoda 545 . 1452 



Usual arrangement of the biliary ducts 545 . 1453 



Remarkable exceptions as to the arrangement of the biliary canals 545 . 1454 



Termination of the bile-ducts in Scyllcea 545 . 1454 



Onchidium 545 . 1454 



Doris . i> ;..._.. .. . 546 . 1455 



Excrementitious secretions of Aplysia . . . 546 . 1456 



Heterogangliate condition of the nervous system in the Gasteropoda 546 . 1457 



