PLATE VI. 
Page. 
Trachypora WilJcinsoni, Eth. fil. ... ... ... ... 2G 
Fig. 1. Vertical microscopic section showing the dense secondary peripheral deposit, the 
axial filled-up corallites, with portions of their median lines left open, and 
crossed by tabula>, x. 4. 
Fig. 2. Similar horizontal section with the sclerenchyma of the axial corallites well 
marked, leaving iir most cases a small central space ; and the peripheral 
corallites gradually bending over to tlieir more or less liorizontal position, as 
evinced by their oblique section, with great thickening of their walls, x. 4. 
Stenopora crinita, Lonsdale ... ... ... ... 49 
Fig. 3. Horizontal microscopic section, exhibiting the polygonal corallites, with alternate 
light and dark concentric rings of secondary sclerenchyma, developed in a 
greater or less degree, x. 7. 
Fig. 4. Similar section, exhibiting the primordial wall, lining of secondary deposit, and 
acanthopores at the corallite angle.s, x. 15. 
Fig. 5. Another section, showing the tibro-concentric structure of the partially-thickened 
walls and the triangular young corallites at the calice angles, x. 50. 
Fig. G. Vertical microscopic section of a few tubes exhibiting a line of moniliform con- 
strictions and the long expanse of simple tubes without taltuhT, x. 8, x. 8. 
Stenopora ovata, Lon.sdale ... ... ... ... 55 
Fig. 7. Vertical peripheral microsco})ic section exhibiting tabula; and the walls partially 
thickened, x. 9. 
Fig. 8. Vertical microscopic section from immediately below the surface showing the 
peculiar form assumed by the moniliform swellings of this species, x. 12. 
Figs. 1, 2, from Mulbring. 
3, 7, 8, „ Singleton. 
4, 5, 6, „ Wollongong. 
N.B. — The enlargements are approximate. 
