CONTENTS. XIII 



SECTION 



3. Nervous System, 146-148 



4. Organs of Sense, 149-151 



I. Organs of Touch, 149 



II. Organs of Vision, 150 



in. Organs of Hearing, • 151 



5. Digestive Apparatus, 152-155 



I. Organs of Deglutition and Mastication, 153 



n. Intestinal Canal, 154 



III. Glandular Appendages, 155 



6. Circulatory System, 156-157 



7. Respiratory System, 158-160 



8. Organs of Secretion, 161 



9. Organs of Generation, 162-169 



IX. THE ACEPHALA. 



Classification and Bibliography, 170 



1. Cutaneous System, 171-175 



2. Muscular System, and Organs of Locomotion, 176-180 



3. Nervous System, 181-184 



4. Organs of Sense, 185-187 



5. Digestive Apparatus, 188-190 



6. Circulatory System, 191-192 



7. Respiratory System, 193-195 



8. Organs of Secretion, . • 196 



9. Organs of Generation, 197-200 



X. THE CEPHALOPHORA. 



Classification and Bibliography, 201 



1. Cutaneous System, 202-203 



2. Muscular System, and Organs of Locomotion, 204-205 



3. Nervous System, 206-209 



4. Organs of Sense, 210-212 



5. Digestive Apparatus, 213-215 



6. Circulatory System, 216-218 



7. Respiratory System, 219-222 



I. Branchiae, 220 



n. Lungs, 221 



ni. Aquiferous System, • 222 



8. Organs of Secretion, 223-224 



I. Urinary Organs, 223 



n. Organs of Peculiar Secretions 224 



9. Organs of Generation, 225-229 



XL THE CEPHALOPHODA. 



Classification and Bibliography, 230 



1. Internal Skeleton, 231-232 



2. Cutaneous Envelope, 233-235 



3. Muscular System, and Organs of Locomotion 236-238 



4. Nervous System, 239-242 



5. Organs of Sense, 243-247 



6. Digestive Apparatus, 248-250 



7. Circulatory System, 251-552 



8. Respiratory Organs 263-254 



2 



