PLATE IV. 



Spirastrella purpurea (Lmk.) Rdl. 

 (Photo's after the original specimens). 



Fig. I. M.M. 62. After a (dried) specimen in the Madras Museum, labelled Suberites inconstans var. 



digitata, probably one of the co-types. 

 Fig. 2. S. E. 305(1. Longitudinal section; two main central canals. On the left hand side (er) the canal is 



distinctly seen to ramify. Natural size. 

 Fig. 3. S. E. 92 a. Longitudinal section, showing two or three main, more or less longitudinal canals (a) ; 



in b a branch of such a canal transversely cut. Natural size. 

 Fig. 4. S. E. 1447. The specimen seen from above. [Compare PI. II, fig. 6]. Natural size. 

 Fig. 5. S. E. 944b. The specimen seen from above'. About 4 / 5 natural size. 



Fig. 6. S. E. 1455 a. The specimen seen from above. e. Uncovered coralline alga; s. sponge-crust. Natural size. 

 Fig. 7. S. E. 1341c. Side view. At a are faint furrows, the last vestige of originally separated, how fused 



processes. Natural size. 

 Fig. 8. S. E. 1975. After a dried specimen. In one of the processes one side is cut away in order to 



show the main central canals, three of which are seen to open at the top. About 



2 / 5 natural size. 

 Fig. 9. S. E. 612a. Longitudinal section. At a a main canal is seen; b holes with barnacles. Natural size. 



