312 Scientific Proceedings, Royal Dublin Society. 



Mouth. — Continually varying; sometimes raised on a cone, 

 sometimes thrown into folds, sometimes widely gaping. Grooves 

 indefinite, each marked with a very inconspicuous pair of tubercles. 

 Oesophagus ribbed and corrugated ; frequently partially protruded. 



Colour. 



Base. — Dirty flesh-colour, changing towards the edge to a pale 

 olive-brown; lines of insertions of mesenteries, same colour. 



Column. — Pale olive-brown below, becoming somewhat darker 

 above; warts somewhat greyer than the surrounding surface, and 

 assuming a darker hue from their transparency when swollen, and 

 when depressed exhibiting a dark spot at their centres; the warts 

 which rise over the parapet often exhibit at their tips some of the 

 white colouring of the tentacles. The lines of the insertions of 

 the mesenteries are of the same colour as the rest of the column. 



Disk, — Lines of insertions of the mesenteries are dark olive- 

 green throughout, the spaces between them and the mouth, and for 

 about one-third of the distance between the mouth and the 

 tentacles, being filled up with opaque white or yellowish- grey ; 

 when the disk is expanded, this arrangement of colour gives the 

 appearance of a series of rays starting from the mouth ; when the 

 disk is contracted, there appears to be a whitish band enclosing the 

 mouth. The rays which start from the oesophageal grooves are 

 crossed by a dark olive line, which separates them from the 

 oesophageal tubercles. 



Tentacles. — Transparent white, pellucid below, more opaque 

 above; sometimes they appear to be marked with more or less 

 intense vertical lines, but a magnifying glass shows that this 

 appearance is due to their surface being fluted when not fully 

 extended, the white lines being slight wrinkles raised on the 

 surface of the tentacles. While the outer covering of the tentacle 

 tube would thus appear to be coloured with white, its inner lining 

 seems to be dark olive, for when the tentacles are reduced to the 

 thread-like condition, they may be seen to possess a dark olive 

 core. 



Mouth. — Oesophagus grey; oesophageal grooves rather whiter, 

 often shining through the transparent olive-green of the disk ; 

 oesophageal tubercles white, inconspicuous. 



