;x GENERAL INDEX. 



Page Sec. 



Structure of its camerated shell 566 . 1517 



Supposed object of camerated structure 566 . 1518 



External organization of Nautilus 566 . 1519 



Structure of the muscular integument of the Cephalopoda . . . 567 . 1520 



Lateral fins of Loligopsis and Onyckoteuthis 567 . 1521 



First appearance of internal organized skeleton . , ; . -.- . . 567 . 1522 



Disposition of cartilaginous skeleton in the CEPHALOPODA . . . 568 . 1523 



Cranial cartilage 568 . 1524 



Rudimentary endoskeleton 568 . 1524 



Exoskeleton 568 . 1525 



Gladius of Loligo 568 . 1526 



Dorsal plate of the Cuttle-fish (os Sepia) 569 . 1527 



Its microscopic structure and uses 569 . 1528 



Mode of growth of the " Cuttle-bone " 569 . 1529 



Shell of the Argonaut 569 . 1530 



Observations of M. Sander Rang on the natural history of the 



Argonaut 570 . 1531 



Experiments of Madame Power 572 . 1534 



Formation of the shell of Nautilus 572 . 1535 



Mouth of the Cephalopoda 573 . 1536 



Oral apparatus of the Cuttle-fish 573 . 1537 



Nautilus 574 . 1538 



Tongue of the CEPHALOPODA 574 . 1539 



Salivary glands 575 . 1540 



Alimentary canal 576 . 1541 



Crop 576 . 1541 



Gizzard 577 . 1542 



Rudimentary representative of the pancreas in Nautilus . . . 577 . 1543 

 the Dibranchiate 



Cephalopods 577 . 1544 



Intestine 577 . 1545 



Liver 577 . 1546 



Secretion of bile 578 . 1547 



Ink-bag 578 . 1549 



Respiratory system 578 . 1550 



Branchial apparatus 578 . 1551 



Mechanism of respiration 578 . 1552 



" Great venous cavity," or " pericardium " 580 . 1553 



Mechanism of siphon of the shell in Nautilus 580 . 1554 



Venous system of the Cephalopoda , 580 . 1555 



Spongy appendages to vena; cava3 580 . 1555 



Supposed functions of spongoid appendages 581 . 1556 



Cribriform parietes of vena cava in Nautilus 582 . 1557 



General arrangement of the circulatory system 582 . 1558 



Branchial hearts . 582 . 1558 



Appendages to branchial hearts 583 . 1559 



Branchial hearts do not exist in Nautilus Pompilius 583 . 1560 



Systemic circulation , . . . 583 . 1561 



Venous sinuses or " lacunae " of Octopus 583 . 1562 



Do not exist in Sepia and Loligo 583 . 1562 



Nervous system of the Cephalopoda 584 . 1564 



Superior development of encephalic ganglia 584 . 1565 



Structure of encephalon . . . . 584 . 1566 



Nervous system of Nautilus Pompilius 585 . 1567 



Supra-cesophageal mass 585 . 1568 



Inferior cesophageal collars 585 . 1569 



Nerves derived from the anterior collar in Nautilus 585 . 1569 



in the DIBRANCHIATA . . 586 . 1570 



Represent the fifth pair in vertebrate animals 586 . 1571 



Posterior suboesophageal ring comparable to the medulla oblon- 



gata of Quadrupeds 586 . 1572 



Nerves derived from it in Nautilus 586 . 1572 



Senses of the Cephalopoda 586 . 1573 



