[693] 
XXII. On the Ciliated Groove {Siphonoglyphe) in the Stornodamm of the Alcyonarians. 
By Sydney J. Hickson, B.A. [Cantab.), B.Stf [Land.), Assistant in the Anatomical 
Laboratory, Oxford. 
Communicated by Professor H. N. Moseley, F.R.S. 
Received May 23,—Read June 14, 1883. 
[Plates 50, 51.] 
Many years ago the distinguished naturalist Gosse (2) described two ciliated grooves 
in the stomach of the Sea Anemones, the function of which is to keep up the circula¬ 
tion of sea-water whilst the animals are retracted, and which he called the gonidial 
canals (“ demicanaux ” of Hollaed (8) and “ schlund-rinnen ” of the German writers). 
These grooves are situated on what are now known as the dorsal and ventral sides 
of the stomach, and their presence has been confirmed and their histology more 
thoroughly investigated by It. and O. He lit wig in their great work ‘ Die 
Actinien’ (7). 
Concerning them these authors say : “ An unseren Durchschnitten durch die 
verschiedenen Actinienarten sind sie tiberall leicht zu erkennen und schienen sie 
sich uns durch eine besonders starke Bewimperung auszureichen.” 
In the genus Cerianthus only one groove is present (Haime) (G), and this is of 
great depth. 
In consequence of the histological difficulties which attend the investigation of the 
Alcyonanans, their minute anatomy has not been very thoroughly investigated, and 
the presence of the ciliated groove on the ventral side of the stomodseum has been 
generally overlooked. The text-books of comparative anatomy do not mention it, nor 
can I find any reference to it in any memoirs except that of the Hertwigs ( l.c .), 
where it is simply stated to be present on the ventral side of the stomodseum, and a 
rough diagrammatic sketch given of it in Alcyonium; and in a paper on Sarcodictyon 
by Gosse (3). 
In the present communication I shall give the result of a series of investigations 
carried on during the last twelve months, for the purpose of tracing this ciliated grove 
through the various genera of Alcyonaria, and in referring to the various parts I shall 
throughout employ the following terms : I shall call the hollow communication 
between the mouth and the body-cavity, which is formed by an invagination of the 
mdcoclxxxiit. 4 u 
