Fig. 1. 
9 
PLATE XXI. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
Fig. 9. 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Tryplasma princeps, Eth.fil. 
Decorticated obconical corallite, with pitted grooves representing the septal lamellae and 
spines, the longitudinal ridges indicating the rugae. 
A portion of the surface towards the base of the same corallite (Fig. 1) more highly 
magnified. 
A portion of a longitudinal section of a corallite, prepared for the m’croscope, showing 
the bases of the septal lamellae, and the tabulae. 
The lower left-hand corner of Fig. 3 highly magnified, displaying the primordial septal 
lamellae. 
Transverse section of a corallite, prepared for the microscope, with the thick peripheral 
septal zone, septal spines, and cut edges of tabulae. 
A small portion of the septal zone, highly magnified. 
Longitudinal section, prepared for the microscope, showing calice, septal spines, and 
tabula?. 
Transverse section of a smaller corallite, prepared for the microscope, exhibiting the 
septal spines and cut edges of tabulae. 
A few of the septal spines, highly magnified. 
Tryplasma congregationis, Ethjil. 
Portions of three corallites in longitudinal section, prepared for the microscope, 
exhibiting, regular complete tabulae ; one of the corallites sends forth two fistulae, 
and two others are seen in transverse section in the matrix. 
Tryplasma wellingtonensis, Eth fd. 
Transverse section of portion of a corallite, prepared for the microscope, showing the 
septal spines and vesicular tabulae. 
A portion of Fig. 11 highly magnified. 
