PLATE VI. 



Archaeolithothamnion erythraeum (Rothpl.) Fosl. f. mollis (Heydr.) Fosl. 



Fig. i. Part of an authentic specimen of Sporolithon ptychoides f. mollis Heydr. from El Tor. 



Fig. 2 — 3. Young and not typical, rather delicate specimens. Stat. 99. 



Fig. 4. A young and typical specimen attached to a piece of coral. Stat. 93. 



Fig. 5. An older one. Stat. 220. 



Fig. 6. A rather young and somewhat stunted specimen burdened with animals and young crusts of other 



calcareous algae. Stat. 81. 



Fig. 7. A specimen surrounding some small object and rather burdened with animals. Stat. 109. 



Fig. 8. A similar one forming transition to f. dura. Stat. 172. 



Fig. 9. A typical specimen surrounding some hard object. Stat. 96. 



Fig. 10. An old specimen. Stat. 71. 



Fig. 11. A similar one rather attacked by animals. Stat. 213. 



