Echin. 1 
XI Y. ECHINODERMA. 
(For 1896 and 1897.) 
BY 
F. A. Bather. 
CONTENTS. 
Page 
Introduction 2 
I. Titles 6 
II. Biology. 
a. Evolution ......... 36 
b. Morphology. 
(i) Anatomy 37 
(This is divided into Classes a— h, as under IV, and 
each Class is subdivided as follows) : — 
1. General Accounts. 
2. Symmetries. 
3. Homologies of Classes. 
4. Skeletal tissue. 
5. Skeletal anatomy. 
6. Hydrocoel and appendages, Respiratory 
organs. 
7. Other body-cavities and their contents. 
8. Digestive system. Cuvierian organs. 
9. Nervous system and sense-organs. 
10. Muscles, connective tissue, joints. 
11. Axial organ. 
12. Generative organs and gonads. 
(ii) Variation 42 
(iii) Secondary Sexual Characters . . . .43 
c. Physiology 43 
Divided as follows: — 
(i) General. 
(ii) Circulation. 
(iii) Respiration. 
(iv) Alimentation. 
(v) Excretion. 
(vi) Sensation. 
(vii) Miscellanea and Experimental, 
