REPORT ON CORALS — HYDROCORALLIN^E. 71 



In the cavities of the pedicles of the more mature lobules a tissue containing a 

 few transparent rounded cells was seen to be present. This may represent a spadix. 

 No rounded spadix such as that occurring in Allopora is present in the interior of the 

 lobules. The histological details were preserved with very great completeness in the 

 present form when hardened in spirit and decalcified, so much so that Plate X. 

 fig. 10, might almost have been executed with a camera lucida from a fine section 

 of a gonophore stained with carmine. It is, however, impossible to determine, with- 

 out close study of fresh material, so difficult a problem as the determination whether 

 the male elements are derived from the ectoderm or endoderm. The apparent 

 development from endoderm cells, in the present instance, may be entirely mis- 

 leading ; the presence of hard skeletons in the Stylasteridse unfits them for research 

 on such points. 



Cryptohelia, M.-Edw. and H. 



A deep-sea coral, dredged in many parts of the world by the Challenger, is referable 

 to the above genus, and although the specimens vary a great deal, they seem not distinct 

 from Milne-Edwards' and Haime's species, Cryptohelia puclica. The specimens, the ana- 

 tomy of which is here described, were dredged off the mouth of the La Plata. 



Ccenosteum of Cryptohelia pudica. 



The ccenosteum is well figured by Milne-Edwards and Haime, 1 and described 2 by 

 these authors as having the form of a small espalier tree, with all the branches 

 comprised in the same vertical plane, and all the calicles turned to the same side (PL XII. 

 fig. 7). As far as the form and arrangement of the branches is concerned, the ccenosteum of 

 Cryptohelia differs in no important particular from that of Astylus subviridis which 

 has just been described. The strise on the surface of the branches are in the present 

 form finer and run for shorter courses than in Astylus stibviridis, and well-marked 

 prominent ridges are not formed between them. 



Regular cyclo-systems are present in Cryptohelia, and are all turned towards one 

 face of the flabellum. Their mouths are not elevated above and isolated from the 

 surfaces of the branches as in Astylus, but the branches swell vertically as well as 

 horizontally where cyclo-systems are present, and the coenenchym of the branch thus 

 rises in a gradual curve to the level of the margin of each cyclo-system (PL XXXV. fig. 7). 



1 Milne-Edwards et J. Haime, Aim. des Sci. Nat., 3 ser., t. xiii., pi. iii. tig. 1, 1850. 

 - Hist. Nat. rles Coralliahes, Paris, 1857, t. ii. p. 127. 



