PLATE II. 



TO ILLUSTRATE THE STRUCTURE OF CORALS. 

 FlO. 

 1 to 8, and fig. 19. The soft parts of Cladocora ccespitosa^ (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 also shown. 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, II. 12, 15, 18, 20.2 The soft tissues of Caryophyllia davits (borealis). Fig. 12. The polype attached 

 to a Ditrupa by a fine peduncle ; the costse 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. 



1.5. The top of a tentacule, magnified, showing scutiform processes aiialogous to the verrucose projections 

 of Cladocora. Figs. 18 and 20. The same processes, highly magnified. 



10. The tentacular discs^ of the corallites of Heliastreea cavernosa, magnified. The mouth is projected 

 on a truncated process, and the tentacular development is small. 



13. LithophtjlHa Cubensis* in the living state. The costse 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. 



1-4. ColpophylUa gyrosaj' from a living specimen. The three mouths to a part of a serial calice. 



I(). Manicina areolata^' showing the relation of the tentacules to the mouths in the serial calice. 



I 7. 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. 



- 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. 



i 1 a c 7 The figures are after Michelotti et Duchassaing, op. eit., pi. v. 



