: COMPARATIVE ANATOMY 



PAGE 



C. LAMELLIBRANCHIA ....... 61 



D. CEPHALOPODA ....... 67 



V. ARRANGEMENT OF THE ORGANS IN THE MANTLE CAVITY, AND 



OF THE OUTLETS OF INNER ORGANS IN THAT CAVITY . 71 



A. GASTROPODA . . . , . . .71 



B. SCAPHOPODA ....... 80 



C. LAMELLIBRANCHIA ....... 81 



D. CEPHALOPODA . . . . . . .81 



VI. THE RESPIRATORY ORGANS ...... 84 



THE TRUE GILLS OR CTENIDIA ..... 84 



A. AMPHINEURA . . . . . . .86 



B. GASTROPODA ....... 88 



C. LAMELLIBRANCHIA . . . . . . .91 



D. CEPHALOPODA . . . . . . .96 



ADAPTIVE GILLS . . . . 97 



LUNGS ........ 99 



VII. THE HYPOBRANCHIAL GLAND ..... 101 



VIII. THE HEAD ... . . .101 



A. GASTROPODA . . . . . . .102 



B. SCAPHOPODA . . . . . . .104 



C. CEPHALOPODA . . . . . . .105 



IX. THE ORAL LOBES OF THE LAMELLIBRANCHIA . . .105 



X. THE FOOT AND THE PEDAL GLANDS .... 106 



A. AMPHINEURA . . . . . . . 106 



B. GASTROPODA . . . . . . .107 



C. SCAPHOPODA . . . . . .112 



D. LAMELLIBRANCHIA . . . . . .112 



E. CEPHALOPODA . . . . . . .115 



XL SWELLING OF THE FOOT (Turgescence) . . . .118 



XII. MUSCULATURE AND ENDOSKELETON .... 119 



A. AMPHINEURA . . . . . . .120 



B. GASTROPODA . . . . . . .120 



C. SCAPHOPODA . . . . . . .123 



D. LAMELLIBRANCHIA . . . . . .124 



E. CEPHALOPODA . . . . . . .126 



XIII. THE NERVOUS SYSTEM . . .128 



A. AMPHINEURA ....... 128 



B. GASTROPODA 132 



