Bull. U. S. F. C. 1900, Vol. 2. — H. L. Claik. (To face page 264.) 
Plate 1 6. 
Fig. 1. Echin<fcucumis asperrima Theel, natural size. 
2. Part of the calcareous ring, x 45. 
3. Part of the body wall from the outside, x 20. 
4. The circle of tentacles (some are broken and some 
may be wanting), x 20. 
Fig. 5. Part of a tentacle, to show the way in which the cal- 
careous rods project, x 90. 
l>. A plate from the body wall near the circle of tenta- 
cles, X 90. 
7. A plate from the base of a tentacle, x 450. 
