s COMPARATIVE ANATOMY 



PAGE 



C. Lamellibranchia . . . .61 



D. Cephalopoda . . 67 



V. Arrangement of the Organs in the Mantle Cavity, and 



OE 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. Amphineuka . 86 



B. Gastropoda 88 



C. Lamellibranchia . , 91 



D. Cephalopoda 96 

 Adaptive Gills 97 

 Lungs . . 99 



VII. The Hypobranohial 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 . . I15 



XI. Swelling of the Foot (Turgescence) . Hg 



XII. Musculature and Endoskeleton II9 



A. Amphineura . . ]^20 



B. Gastropoda 220 



C. Scaphopoda . _ j.^3 



D. Lamellibranchia _ 124 



E. Cephalopoda . . _ ^26 



XIII. The jSTbrvous System j28 



A. Amphineura . . . -[28 



B. Gastropoda . j32 



