Fic. 
PLATE II. 
TO ILLUSTRATE THE STRUCTURE OF CORALS. 
1 to 8, and fig. 19. The soft parts of Cladocora cespitosa' (after Jules Haime). Fig. 4. The tentacules, 
tentacular disc, mouth, and radiating lines on the lips. Fig. 3. Magnified view of a 
section of part of a tentacule; the arrangement and nature of the nematocysts and of the large 
transparent vesicles of the verrucose prominences are shown; the structure of the internal layer, 
with its colour-bearing cells, is alsoshown. Fig. 1. A portion of the terminal swelling of a 
tentacule; the two kinds of nematocysts are very well seen. Figs. 5, 6, 7, 8. Nematocysts 
of the terminal swelling. Fig. 2. The tubular processes attached to mesenteric folds; they 
are covered with cilia, and contain nematocysts. Fig. 19. A portion of a tentacule, magni- 
fied, showing the terminal swelling and the verrucose swellings. 
9, 11, 12, 15, 18, 20.2. The soft tissues of Caryophyllia clavus (borealis). Fig. 12. The polype attached 
10. 
to a Ditrupa by a fine peduncle; the coste are seen to be covered with a transparent tissue, 
which gives them a rounded outline; the tentacules overlap the calicular margin, and are fully 
expanded (slightly magnified). Fig. 9. The tentacules of various orders fully expanded, the 
central mouth, the lips, and the disc immediately around them, with the radiating lines, are 
shown. The hard parts of the calice are completely covered and hidden. Fig. 11. A 
magnified view of the tentacular disc, the tentacules not being fully expanded. The septa 
are seen, but are covered with soft tissue. The mouth, lips, and disc, with the radiating lines, 
are shown. 
The top of a tentacule, magnified, showing scutiform processes analogous to the verrucose projections 
of Cladocora. Figs. 18 and 20. The same processes, highly magnified. 
The tentacular discs* of the corallites of Heliastrea cavernosa, magnified. The mouth is projected 
on a truncated process, and the tentacular development is small. 
Lithophyllia Cubensis,* in the living state. The costa are quite hidden by the soft parts, and 
the large disc, with its central mouth and radiating lines, is seen. The base is very broad. 
Colpophyllia gyrosa,° from a living specimen. The three mouths to a part of a serial calice. 
Manicina areolata,® showing the relation of the tentacules to the mouths in the serial calice. 
A coral of the same species,’ with the prehensile cirrhi fully expanded. The tentacules are small, and 
there are two mouths to the serial calice. 
' «Hist. Nat. des Corall.,’ vol. ii, plate, a, iv. 
9 
* These beautiful illustrations were drawn for me, from nature, by Mr. Peach, who also gave me his 
notes on the anatomy of the C. borealis, Fleming. 
34567 The figures are after Michelotti et Duchassaing, op. cit., pl. v. 
