696 
MR. S. J. HICKSON ON THE CILIATED GROOVE 
of the stomodseum frequently as far as the insertion of the ventro-lateral mesenteries, 
and the cilia are characteristically long and strong (Plate 50, fig. 5). 
It is exceedingly probable, from these facts, that the great part of the circulation in 
Sarcophyton is carried on by the siphonozooids, whilst the autozooids carry on the 
same function to a much smaller extent. 
The genus Paragorgia is also dimorphic, a fact which seems to have been previously 
overlooked, and here we find a condition concerning the siphonoglyphe slightly 
different from that found in Sarcophyton, 
After a careful examination of numerous autozooids, both in the retracted and 
.expanded condition, I could find no trace of a true siphonoglyphe. There seems to be 
no marked thickening of the epithelium on the ventral side of the stomodseum, nor 
are the cilia markedly longer or stronger in that region (Plate 50, fig. 6). 
In the siphonozooids, however, the siphonoglyphe is remarkably strong, and extends 
as far round the stomodseum as the insertion of the latero-ventral mesenteries, whilst 
the long cilia reach half-way across its lumen (Plate 51, fig. 8). 
In Paragorgia , as in Siphonogorgia, the ova are borne by the. siphonozooids, and 
frequently they are so full of them as to cause the stomodseum to be pushed to one side 
and the mesenteries to be broken (Plate 51, fig. 7). 
A similar condition to this was found in the genus Heteroxenia. No trace of a 
siphonoglyphe could be seen in the autozooids, whilst a well-marked one was found in 
the stomodseum of the siphonozooids. 
Amongst the Pennatulida I have examined two genera, Pennatula and Renilla. In 
the autozooids of Pennatula I could find no siphonoglyphe, nor in the autozooids of 
Renilla. Kolliker (9) does not mention any ciliated groove in any of the numerous 
Pennatulids he examined, nor does Marshall (17) in Pennatula, Funiculina and 
Virgularia. I think therefore I am justified in concluding that the siphonoglyphe 
does not exist in the autozooids of the Pennatulida. In the siphonozooids, however, 
a well-marked siphonoglyphe exists ; in Pennatula it occupies a considerable portion of 
the stomodseum (Plate 51, fig. 10), and is armed with numerous long and strong cilia; 
in Renilla it is remarkable for its enormously long cilia, which stretch right across the 
lumen of the stomodseum (Plate 51, fig. 9). 
Thus it will be seen that in the dimorphic Alcyonarians the siphonoglyphe has a 
tendency to disappear from the autozooids and to become very prominent in the sipho¬ 
nozooids. In Sarcophyton it still remains in the autozooids, but considerably diminished 
both in size and importance; in Paragorgia, Heteroxenia, and Pennatulida it has 
completely disappeared from them, whilst in all forms a well-marked siphonoglyphe 
is present in the siphonozooids. 
In the genus Ilelioptora, some specimens of which Professor Moseley has kindly 
placed at my disposal, a siphonoglyphe of moderate dimensions is present. 
Amongst the Gorgonidae I have examined only two genera, Villogorgia and Primnoa, 
and in neither of these could I find any trace of a siphonoglyphe. In the genus 
