468 Mr. J. Macgillivray on Marine Zoojihytes. 



existing between each two parallel cells. Only a single specimen of 

 this very distinct species has occurred to me, attached to a fragment 

 of limestone from deep water. Not haAing been able to find it de- 

 scribed, 1 have ventured to give it a specific name taken from one of 

 its most prominent characters. 



Memhranipora pilosa. On various fuci and corallines ; common. 



Flustra foliacea. This varies much in its mode of division. Ex- 

 tremely abundant. 



F. truncata. Equally common with the preceding. 



F. carbasea. Generally but not alwa^^s attached to shells ; very 

 common here, where it was discovered about a century ago by Dr. 

 Skene, who sent it to ElUs. 



F. memhranacea. Covering the frond of Laminaria digitata and 

 Fucus nodosus, especially the former ; abundant. 



Cellularia scruposa. On corallines, shells, &c. ; plentiful. 



C. reptans. Not quite so abundant as the preceding, but still 

 common. 



Farcimia slnnosa, Hassall, Ann. and Mag. Nat. Hist. vi. p. 172. 

 pi. 6. By a careful examination of a very fine specimen selected from 

 an extensive series, I have found a great variation in the form of the 

 cells. These are generally " rounded above and excavated below for 

 the reception of the head of the succeeding cell," as they are de- 

 scribed by Mr. Hassall, but between this form and a perfect rhom- 

 boid there exists an obvious gradation. Rhomboidal cells are found 

 chiefly upon the terminal articulations, but occur also throughout the 

 polypidom along with the much more numerous spathulate cells. 

 In Mr. Hassall's specimens the aperture was invariably " situated in 

 the upper third of each cell ;" in mine, however, the aperture is oc- 

 casionally " exactly central ;" it often commences at the middle of 

 the cell, although stiU more frequently at a little above this. Not 

 having seen an undoubted specimen of F. salicornia, or one ha-\-ing 

 all the cells rhomboidal, and all their apertures " exactly central," it 

 would be presumption in me to off"er any opinion regarding the spe- 

 cific distinctness of the F. sinuosa of Mr. Hassall, to whom we are 

 indebted for the correction of several errors which had crept into 

 zoophytology, as well as for the discovery of many new and inter- 

 esting species. Brought up by the fishing-lines from a depth of be- 

 tween forty and sixty fathoms, a bank covered by this depth of 

 water being situated about ten miles off the land ; not uncommon. 



Alcyonidium gelatinosum. Don-Mouth. 



A. hirsntum. Shore north of the harbour ; like the preceding. I 

 met M'ith it only once. 



A. parasiticum. Upon Sertularia argentea and many other coral- 

 lines, once upon Crassina Damnoniensis, and frequently upon stones ; 

 very common. 



Cliona celata. A small Annelide inhabits perforations, the orifices of 

 which are very similar to those in which the Cliona is found ; with 

 respect to the latter, however, I could not have been mistaken, ha- 

 ving repeatedly oberved the living zoophyte projecting about a line 

 beyond the orifices in the shell which it inhabited. Found in per- 



