720 
DE. WYVILLE THOMSON ON HOLTENIA. 
PLATE LXX. 
Fig. 1. A section of one of the trabeculae of the substance of the sponge, showing the 
origin of two of the fascicles of spicules of the beard, which pass through the 
outer wall of the sponge at a and b. x20. 
Fig. 2. Vertical section of the sponge-substance from the upper part of the sponge, 
near the edge of the osculum. X 20. 
PLATE LXXI. 
Fig. 1. Holtenia Carpenteri, young. x50. 
Fig. 2. Holtenia Cakpenteri, somewhat more advanced, x 5. 
Fig. 3. Section through the specimen, tig. 2. x 5. 
Fig. 4. Another specimen, x 5. 
Fig. 5. Oscular surface of the same, seen from above. x5. 
Fig. 6. A somewhat younger specimen. X 5. 
Fig. 7. One of the spicules of the outer wall of the sponge, tig. 3. x50. 
Fig. 8. Bihamate spicule of the beard. X 100. 
Fig. 9. Begular six-rayed spicule from the substance of the sponge, tig. 2. x 100. 
Fig. 10. Nearly similar spicule from the same sponge. X 100. 
Fig. 11. Small serrated spicule of the sarcode. X 1 00. 
Figs. 12, 13. Feathered spicules of the sarcode from the outer wall. xl00. 
Fig. 14. Hexradiate feathered spicule, possibly from the netted lid of Aphrocallistes, 
and accidentally entangled in the young Holtenia (fig. 2). x 100. 
Figs. 15, 16, 17. “Amphidisci.” xl00. 
Fig. 18. Serrated projecting spicule from the surface of the sponge. xl00. 
