GENERAL INDEX. 



Sense of touch . 586 



Structure of the cephalic apparatus in Nautilus Pompilius . . . 587 



Lateral processes 587 



Antenniform tentacula - * 587 



Labial processes and their cirri .- . . . . . . 587 



Nerves of the prehensile arms of the DIBRANCHIATA . . ... 589 



Sense of taste . . . ; i .".<. 589 



Olfactory apparatus 589 



in Nautilus 590 



Eyes of the CEPHALOPODA 590 



Nature of the eye of Nautilus 590 



Structure of the pedunculated eyeball of Nautilus 591 



Structure of the eye in the DIBKANCHIATA 592 



Orbital cavity 592 



Anatomy of the eye of Sepia officinalis 592 



Muscles of the eyeball 596 



Progressive development of the organ of hearing 596 



Auditory apparatus of the DIBRANCHIATE CEPIIALOPODS .... 596 



Structure of the ear in Sepia officinalis 596 



Generative system of the Cephalopoda 598 



Ovaria of the female Cuttle-fish 598 



Structure of oviduct 598 



Ova of the Cephalopoda 599 



Generative apparatus of male Cuttle-fish 600 



Pouch of Needham 601 



Male sexual organs of the Argonaut 601 



Hectocotylus Argonauts 601 



Penis 602 



Embryonic condition of the young 603 



Chromatophores 604 



Fossil Cephalopoda 604 



Ammonites 604 



Hamites, Lituites, Orthoceratites, &c 605 



Spirula 605 



Bekmnites . 605 



CHAPTER XXV. 

 VEETEBEATA. 



VERTEBRATA General view of this division of the animal kingdom . 606 



Internal osseous skeleton 606 



Progressive ossification of the bony framework 606 



Observations on the skeleton in general 607 



Composition of typical skeleton 607 



Vertebral column 608 



Cranial vertebrae 608 



Framework of the face 608 



Lateral arches 608 



Hyoid apparatus 608 



Eibs 609 



Limbs 609 



Elements of the skeleton 610 



Composition of a vertebra 610 



the thorax 611 



Skeleton made up of vertebral segments 612 



Elements constituting a complete or typical vertebra 612 



Vertebras of osseous fishes 614 



air-breathing Vertebrata 614 



" Diverging appendages " 614 



convertible into limbs 614 



