Grajella, Osciili-ia, and Cliona. 81 



"where, under Dr. Gray's name of " Pione^^'' he states that 

 Cliona northumhrica is not uneommonly di'cdged off the south 

 coast of Devon, " in Buccinum undatum and in tlie ohl valves 

 of Cardium edule^^ testifying at the same time to the " excel- 

 lent" description of this species, in the 'Annals,' by Mr. 

 Albany Hancock. 



In my specimen, which is not much the worse for ten days' 

 confinement, there are no raised areola? of sponge-substance 

 (spicules and sarcode) bordering the holes in the oyster- 

 shell, as in the specimens of Cliona celuta and Raijliyrus 

 Grirfjithsii to which I have alluded ; and I think it not impro- 

 bable that, although the papilla? would be much contracted by 

 death, still some of them would remain much beyond the 

 holes in the oyster-shell, which, if dissolved off, would give 

 them a similarly elevated position above the other s])onge- 

 substance to that presented by the papilla? in Grayella and 

 Osculina, 



Postscript. 



Since the above was written, three or four of the inhalant 

 papillte, now in a semicontracted condition, on the concave 

 side of the oyster-shell, have presented a single funnel- 

 shaped hole in the centre respectively, which, being so much 

 larger than the original apertures, led me to think that they 

 must be vents ; but on placing them under the microscope, 

 particles were observed to be whirled into them, apparently in 

 a spiral manner, shcJwing at once that they were not vents, 

 and affording positive evidence, Avhich had not been before 

 obtained, of the inhalant function of these papilla?. 



The vents are still active, and the inhalant papilla? as sen- 

 sitive to light as when first the Cliona was placed in con- 

 finement (now thirteen days ago), Avhich would hardly have 

 been the case had the Cliona not been drawing its nourish- 

 ment from the organic matter in the oyster-shell. On the 

 other hand, a living piece of Raphyrus Gri-fjithsii (which I 

 regard as a free form of Cliona celata)^ and Avhich was placed 

 in sea-water renewed as often as that of the Clio7ia, ceased, 

 after three days, to show any active signs of life Avhat- 

 ever. 



The papilla? which presented respectively the single funnel- 

 shaped hole in the centre were, with the exception of the rim, 

 very like Schmidt's figs. 10 & 11 of Oscidina polystomella 



Finally, it should be noticed that the papilla? in Cliona 

 northumhrica ceased to ])resent their fimbriated forms about 

 the sixth day after confinement, and, showing signs of decline 



