12 Echin. 
V. E chino derma. 
[1920] 
8. Parasites and Commensals. 
Pelseneer, 107. 
12. Geological aspect. 
Fourtau, 58 ; Kew, 85 ; Ulrich, 129. 
13. Phenology. 
Clark, 83. 
15. Echinoderms as food. 
Kjerskog-Agersborg, 89. 
VARIATION AND ETIOLOGY. 
1023 
1. Variation in form. 
Foerste, 52 ; Wright, 188. 
2. Variation in colour. 
Clark, 33. 
2. Variation, meristic, numerical. 
Foerste, 52. 
5. Variation, teratological. 
Cotte, 37 ; Foerste, 52. 
7. Variation, mutational. 
Foerste, 52 ; Wright, 138. 
8. Evolution. 
Hawkins, 67 & 68 ; Kew, 85. 
10. Phylogeny. 
Foerste, 52 ; Hawkins, 68 ; Kew, 85 ; 
Springer, 117 ; Thust, 128. 
DISTRIBUTION. 1027 
A. Geographical. 
11. Atlantic Ocean, etc. 
Burnley, 17 ; Clark, 33 ; Garstang, 
60 ; Gilchrist, 63 ; Massy, 96 ; Renouf, 
110; Stephensen, 120; Vayssi&re, 130 & 
131. 
iii. Indian Ocean. 
Doderlein, 45 ; Hawkins, 68 ; Smith, 
115 ; Voeltzkow, 132. 
iv. Pacific Ocean, etc. 
Clark, 30 & 32 ; Doderlein, 45 ; 
Hawkins, 68 ; MacBride, 94. 
v. Arctic Ocean, etc. 
Stephensen, 120. 
vi. Antarctic Ocean, etc, 
Helier, 69 ; MacBride, 94. 
vii. Malaysia. 
Clark, 28 ; Doderlein, 45. 
B. Geological. 
ii. C&inozoic. 
a. General. 
Baker, 6 ; Collot, 36 ; Spongier, 116. 
b. Pleistocene. 
Kew, 85. 
c. Pliocene. 
Airaghi, 3 ; Checchia-Rispoli, 26 ; 
Fourtau, 58 ; Kew, 85 ; Roig, 111. 
d. Miocene. 
Airaghi, 3 ; Berz, 13 ; Chapman, 
24 ; Checchia-Rispoli, 26 ; Fourtau, 
58 ; Hume (and others), 74, 76, & 78 ; 
Kew, 85 ; Madgwick, 95 ; Roig, 111. 
e. Oligocene. 
Castex & Lambert, 22 ; Clark, 31 ; 
Maury, 97. , 
f. Eocene. 
Castex & Lambert, 22 ; Douvill6, 48 ; 
Gregory & Currie, 66 ; Hume (and 
others), 74 & 77 ; Kew, 85 & 87 ; 
Oppenheim, 104 ; Stefanini, 119 ; 
Welsch, 184. 
iii. Mesozoic. 
a. General. 
Cayeux, 23. 
b. Cretaceous. 
1. Upper Cretaceous 
Brouwer, 15 ; Brydone, 16 ; Butler, 
18 ; Douvillfe, 48 ; Gregory & Currie, 
66 ; Kew, 85 ; Kitchen & Pringle, 
88 ; Moncton, 101 ; Stefanini, 118 & 
119; Thuma, 127. 
2. Lower Cretaceous. 
Checchia-Rispoli, 25 ; Fossa-Man- 
. cini, 57 ; Gemmellaro, 61 ; Hume (and 
others), 75 ; Kew, 85 ; Moncton, 101 ; 
Parona, 106. 
