REPORT ON THE ALCYONAEIA. 187 



SO for a long time, but it is not impossible that it lived at the depth at which it was 

 dredged." Mr. Ridley, who examined specimens of this Coral, thought it was probably 

 to be referred to PleurocoralUumjohnsoni, Gray, which occurs at Madeira. 



Apparently the same species was again met with at Station 85, off the Island of 

 Palma, in 1125 fathoms. It may possibly be a deep-sea form. 



Order II. PENNATULACEA. 



The families, genera, and species belonging to this family have been already described 

 by Professor A. von KoUiker.^ 



Order III. ALCYONACEA. 

 Family I. H e l i o p o R i d .e, Moseley. 



Helioporidx, Moseley, PhiJ. Trans., vol. clxvi. p. 91, 1876. 



A compact coraUum is present, composed of a fibro-crystalline calcareous tissue as 

 in Madreporaria. CoraUum consisting of an abundant tubular coenenchyma, and with 

 calycles having an irregular number of lateral ridges resembling septa. Calycles and 

 ccenenchymal tubes closed below by a succession of transverse partitions. Polyps com- 

 pletely retractile, with tentacles when in retraction introverted. Mouths of the sacs lining 

 the ccenenchymal tubes closed with a layer of soft tissue, but communicating with one 

 another and with the calycular cavities by a system of transverse canals of soft tissue. 



We place this family in close connection with the families Nephthyidse and Alcyonidse; 

 in conformity, as we believe, with the views of Professor Moseley, whose researches on 

 Heliopora coerulea have completely revolutionised our knowledge of the family. 



Genus Heliopora, Blainville, emend. Moseley. 



Colony compact, branching, tissue calcareous as in Madreporia. Calycles with from 

 eleven to sixteen plications ; eight symmetrically and radially disposed lobes form a 

 covering closing the mouths of the calycles. Polj^ps retractile ; the colonies probabl)' 

 unisexual. 



Heliopora coerulea, Blainville. 



Heliopora coerulea, Blainville, Manuel d'Actinologie, p. 392, pi. Ixi. fig. 3. 

 ,, „ Milne-Edwards, Hist. Nat. des Coralliaires, vol. iii. p. 231. 



„ „ Moseley, Phil. Trans., vol. clxvi. p. 91. 



This species has been so well and fully described by Professor Moseley {loc. cit.) that 

 it is unnecessary to give further details here, the more so as only a small fragment of 



1 Vide Zool. Chall. Exp., vol. i. part ii. 



