PLATE XXIII. 
Fig. 1. 
Tryplasma princeps, Eth.fi], 
A longitudinal section, prepared for the microscope, of a large cylindrical corallite, 
showing the thickened wall and broken-up tabulae. 
Fig. 2. 
A similar section of part of another cylindrical corallite, exhibiting the thickened wall, 
and septal spines ; the tabulae are less broken up, some complete, others forming 
lenticular vesicles. 
Fig. 3. 
A portion of the wall of Fig. 2, showing the septal spines. 
Fig. 4. 
Tryplasma vermiformis, Eth fid. 
Longitudinal section of a corallite, prepared for the microscope, showing the distant, 
complete, and horizontal tabulae ; in one of the latter is a peculiar medium dip. — x 2L 
Fig. 5. 
Transverse sections of four corallites, prepared for the microscope ; one of these shows 
a very beautiful example of compound calicular rejuvenescent budding. 
Fig. G. 
Tryplasma delicatula, Eth. fid. 
Longitudinal section of several corallites, with fistuke and tabular spines. — x 2. 
Fig. 7. 
A small portion of one of the corallites highly enlarged. 
Fig. 8. 
Tryplasma, sp. 
Longitudinal section, prepared for the microscope, of portions of two corallites of the 
coral represented in PI. XVI, Figs. 1 and 2, showing the septal spines and 
complete tabulae. — x 2. 
# 
Tryplasma dendroidea, Eth. fid. 
Fig. 9. 
Transverse section of a corallite, prepared for the microscope, showing delicate short- 
acicular septal spines, and the wide tabulate area. — x 2. 
Fig. 10. 
Tryplasma congregationis, Eth. fid. 
Transverse section of one and a half corallites, prepared for the microscope, with similar 
septal spines to those in Fig. 9. In the right-hand half-corallite is a portion of a 
rejuvenescent bud (?). 
