OCTINEON LINDAHLI. 477 



EXPLANATION OF PLATES 29 and 30, 



Illustrating Dr. G. H. Fowler's paper on "Octineon 

 Lindahli" (W. B. Carpenter). 



PLATE 29. 



These figures have been reproduced from the two quarto plates prepared 

 by Dr. W. B. Carpenter, but never published. Professor H. N. Moseley 

 wrote out an unrevised description of these plates, of which such part as 

 relates to the figures selected for reproduction is here printed. My own 

 additions are enclosed in square brackets, 



I have been reluctantly compelled to differ from Professor Moseley in 

 interpreting his " stomodceum " as the upper part of the column, his " ten- 

 tacular chamber " as the oral disc, and his "stomach" as the stomodjEum. 

 Continuous series of microscopic sections (so far as I am aware, he was not 

 at work long enough upon the animal to have these prepared) and a com- 

 parison with an ordinary Actinia in complete retraction, have left no doubt in 

 my own mind as to the correctness of these interpretations, but I have 

 thought it only just to him to present his actual words, and to make my own 

 alterations in brackets. 



Fig. 1. — A typical specimen, enlarged about [seven] diameters, viewed from 

 the oral face. The entire surface is thickly set with fine sand grains, frag- 

 ments of foraminiferous shells, spicules, fee. At the summit of the central 

 visceral prominence is seen the opening of the invagination of the surface 

 leading to the mouth. 



Pig. 2. — A closely similar specimen viewed from the aboral face, with the 

 adherent sand particles completely removed. The finer radial striae mark the 

 courses of the mesenteries ; some of the broader radiating ridges correspond 

 with some of the eight large retractor muscles [and their associated mesen- 

 teries. Judging by the shading of the drawing, I have no doubt that 

 " aboral " was only a slip of the pen for " oral ;" the aboral surface is very 

 nearly flat, but in the centre of this drawing is a cone with a central pit.] 



Pigs. 3, 4, and 5. — Examples, with the adherent sand removed, showing 

 irregular varieties in [the] form assumed, produced by the indentation of the 

 margin and the outgrowth of lobes. 



Pig. 6. — Ttie invaginated stomodseum [oral disc, and inturned column] 

 removed from the body-cavity. At its base are seen [ten of] the evagiuated 

 tentacles [lying in pouches of the oral disc] which there [surround ?] the 

 mouth, the entrance to the oesophagus. 



