C. L. Edwards 
237 
Page 
H. Calcareous Spicules of the Ambu- 
lacral Appendages and the Dif- 
ferentiation of Pedicels and 
Papillae 264 
a. Form 265 
b. Suckers 265 
c. End-plates .... 265 
d. Supporting Rods . . . 266 
1. Dorsal 266 
2. Ventral 266 
e. Association of Forms of Ambula- 
cral Appendages with Tyi)es 
of End-plates . . . 266 
f. Association of Suckers with 
Types of End-plates . . 267 
g. Association of Supporting Rods 
with Types of End-plates . 267 
h. Conclusions and Definitions . 267 
I. The Calcareous Ring . . . 268 
J. Polian Vesicles .... 269 
K. Stone-canals and Madreporites . 271 
L. Gonads 273 
M. Respiratory Trees . . . 273 
N. The Enteric Canal . . . 273 
0. Habitat 274 
III. Holothuria atra Jiiger . . . 274 
A. Body 274 
a. Form 274 
b. Size 274 
1. Length in cm. . . . 274 
2. Diameter in cm. . . . 277 
3. Volume in cm.^ . . . 277 
B. Colour 277 
a. Colouration .... 277 
1. Pedicels and Papillae . . 277 
2. Disti'ibution of Colour on the 
Body .... 277 
C. Tentacles and Ampullae . . 278 
a. Number of Tentacles . . 278 
Variation in the Number of 
Tentacles and the Relation 
of those present to the 
Normal Symmetry . . 278 
b. Branches on Tentacular Am- 
pullae and Variation in their 
Number .... 279 
D. Pedicels and Papillae . . .279 
a. Distribution per sq. cm. . . 279 
b. Distribution of Papillae around 
the Anus . . . .280 
E. The Body-wall .... 280 
Page 
a. Thickness in nun. . . . 280 
b. Pits 281 
F. Calcareovis Spicules of the Body- 
wall 282 
a. Tables 282 
b. Tables of Biviuui and Trivium 
in H. atra .... 282 
1. Disc 283 
2. Height 283 
3. Crown ..... 283 
c. Rosettes and Rosettes witli 
Holes 283 
Number per sq. cm. . . 285 
G. Calcareous Spicules of the Anil )u- 
lacral Appendages and the Dif- 
ferentiation of Pedicels and 
Papillae 285 
a. Form 285 
b. Suckers ..... 285 
c. End-plates .... 286 
d. Supporting Rods . . . 286 
Dorsal 286 
e. Supporting Rosettes and Sup- 
porting Plates. Ventral . 287 
f. Association of Form of Anibu- 
lacral Ap2icndages with Types 
of End-plates in the Bivium 287 
g. Association of Suckers with 
Types of End-plates . . 287 
h. Association of Supporting Rods 
with Types of End-plates . 287 
i. Conclusions and Definitions . 288 
H. The Calcareous Ring . . .288 
I. Polian Vesicles .... 288 
J. Stone-Canals and Madreporites . 289 
K. Gonads 290 
L. Respiratory Trees . . . 290 
M. The Enteric Canal . . .290 
N. Habitat 290 
IV. Summary 292 
A. Characters sei)arating //. flori- 
dawx Pourtales { = 11. inexicana 
Ludwig, H. africana Theel)from 
H. atra Jiiger . . . .292 
B. Characters Common to the Two 
Species 294 
C. Additional Characters of H.flori- 
dana ..... 295 
D. Additional Characters of H. atra 296 
Litei-ature cited .... 297 
Explanation of Plates . . 300 
