48 Proceedings of the Royal Physical Society, 



Unfortunately none of the polypes whicli I examined or 

 sectionised contained reproductive organs. I searched most 

 carefully over the free edges of the mesenteries in a number 

 of sections, but was unable to find anything which could 

 be considered as even the young condition of ova or sperm 

 cells. Gosse/ in describing his living specimen, talks of 

 a mass at the lower end of the body which he saw through 

 the body walls, as being probably the ovaries on account 

 of its opacity, but possibly it was merely the thickened 

 mass of craspeda which I have described above. It is 

 not even known yet whether or not all the polypes in a 

 colony of Sarcodictyon are of one sex as is the case in Penna- 

 tida^ and many other Alcyonaria. I hope to investigate this 

 and a few other undetermined points in fresh material on 

 some future occasion. 



IV. Final. 



In conclusion, the two forms which I dredged in Loch Fyne, 

 and which I have referred to above as the red and the yellow 

 " varieties," seem to differ in nothing but colour, which is due 

 to the spicules in the one case being of a red tint, while in 

 the other case they are colourless. Hence both forms must 

 be considered as Sarcodictyon catenata (Forb.). In Alcyoniitm 

 digitatum in the same way two very distinct colours of colony 

 are found. 



I have not seen Forbes' Sarcodictyon agglomerata^ and can 

 judge of it merely from his figures and the original description 

 in which two points of distinction from >S'. catenata are speci- 

 fied: — (1.) the polypes are not arranged in single file, but are 

 grouped together in assemblages of from 3 to 5, each group 

 being connected with its neighbours by a stolon ; and (2.) the 

 colour is " ochraceous yellow." Now, in several of my colonies 

 of the red variety of Sarcodictyon catenata, here and there the 

 polypes are not placed in single file, but form small groups 

 united by a continuous basal expansion which gives off the 

 ordinary narrow stolons leading to other polypes or groups of 



1 Loc. cit, p. 278. 



" See Marshall's Report on the Oban Pennatulida, Birmingham, 1882. 



