IN THE STOMOMUM OF THE ALCYONARIANS. 
697 
Villogorgici, although my specimens were most excellently preserved, I could find no 
cilia on any part of the stomodseum. I do not wish to assert for a moment that they 
do not exist, but if they do they must he exceedingly minute to show no trace in 
preserved specimens. The epithelial cells are filled with minute highly refracting 
particles, which conceal their outlines in exactly the same way as Marshall has described 
in the stomodseum of Funiculina (17, p. 14). 
An interesting feature in the stomodseum of Villogorgia is the presence of a deep 
groove on the dorsal side (Plate 51, fig. 11), which is not beset, as the siphonoglyphe is, 
with long cilia. The epithelium of this dorsal groove is thinner than it is in other parts 
of the stomodseum. I have found nothing that corresponds with this dorsal groove 
in anf other Alcyonarian. 
In the genus Frimnoa, again, I could find no trace of a siphonoglyphe, either in fully 
grown polyps or young buds (Plate 51, fig. 12). 
Yon Koch does not describe a siphonoglyphe in any of the numerous Gorgoniche he 
has examined (Isis, Gorgonia, Sclerogorgia, &c.), so that it seems to me probable that 
it does not exist in the stomodseum of Gorgonidse, or, at any rate, in those Gorgonidse 
with polyps that are not completely retractile. 
It must be remembered in reference to Von Koch’s evidence that this author did not 
describe a ciliated groove in Tubipora, where it is undoubtedly present; but in this 
genus the stomodseum of the retracted polyps is so folded and creased that unless 
exceedingly thin sections are made it is easily overlooked, whereas in the non-retractile 
polyps of many Gorgonidse where the stomodseum is not much folded a simple series 
of transverse sections would show it at once were it present. 
General observations on the presence of the siphonoglyphe in the Alcyonaria. 
In the three genera which have been described of simple Alcyonaria which do not 
form colonies, namely— Monoxenia (Haeckel, 5), Hartea (Wright, 20), and Haimea 
(M. Edwardes, 18 ), no siphonoglyphe has been described, and considering the small 
area that the circulation of these animals has to traverse, it seems to me probable that 
it does not exist in them. Where, however, a wider circulation was introduced, owing 
to the formation of complicated colonies, the aid to the circulation afforded by a 
siphonoglyphe became necessary. 
In Clavularici, in which the colony consists of a number of polyps standing on a 
thin sto]on, the circulation is not very extensive, and consequently we find that the 
siphonoglyphe is not very strong. In genera such as Alcyonium, Spongodes, Nephthya, 
&c., where there are long body-cavities and a considerable amount of gelatinous 
sarcosoma, a stronger circulation is necessary, and consequently we find that the 
siphonoglyphe has assumed more important proportions. 
As long as the siphonoglyphe is confined to that portion of the wall of the stomodseum 
which lies between the two ventral mesenteries there is probably but little interference 
with the other functions of the stomodseum ; but when the necessities of the circula- 
