136 Proceedings of the British Association. 



fyc.) by the form of their tentacula, and the free, arborescent nature 

 of their branchiae. These characters alone induced the authors to 

 consider them generically distinct, before they had an opportunity of 

 examining their internal structure, in which such important differences 

 in the digestive organs were exhibited as to show that this new 

 genus — for which the name of Dendronotus is proposed — should be 

 removed from the family Dorididse to that of Eolididse, to be placed 

 first in order, as the connecting link between these two families. 



The paper was illustrated by drawings from the work by Messrs. 

 Alder and Hancock on the British Nudibranchiate Mollusca just 

 published by the Ray Society. 



Prof. Allman remarked, that this paper was important, as it more 

 clearly than ever demonstrated the errors into which M. de Quatrefages 

 had fallen with regard to this family. 



' On the Cilia and Ciliary Currents of the Oyster,' by the Rev. J. 

 B. Reade. — The author stated, that in a microscopic investigation of 

 Infusoria, which had for some years occupied his attention, he had 

 been led particularly to notice the beautiful contrivance by which 

 many species, when not exerting their powers of locomotion, are 

 supplied with food. "When they are examined under the microscope 

 by such an arrangement of transmitted light as makes the Infusoria 

 luminous points on a perfectly dark field, it is immediately seen 

 that the action of the cilia attached to their tentacular, produces 

 a strong current in the water, and hereby a countless number of 

 minute living organisms is brought within the influence of the cilia, 

 and a sufficient supply is selected for food. Thus, with respect to 

 Infusoria, it is a known fact, that the absence of the prehensile organs 

 possessed by larger creatures is compensated by this delicate, but 

 efficient ciliary apparatus. It is also a fact equally well known, 

 that the lips of the oyster, which surround the orifice of the ali- 

 mentary canal, are, in the same manner, fringed with cilia ; and that 

 these cilia of the oyster, as of Infusoria, equally cause currents 

 in the water. But it has never been suggested and proved by any 

 naturalist that the proper office of the cilia of oysters is to bring to 

 these acephalous mollusks that food which they have no power to 

 follow or to seize. Such, however, without doubt, is the case ; and, 

 accordingly, an examination of the contents of the stomachs of 



