Happon and DurrpEN—Some Actiniaria from Australia and other Districts. 157 
‘¢ This species is remarkable for its straight sides, resembling a tower, although 
it is very soft; by the number of smooth, oval tubercles which cover it in 
vertical rows, which are sometimes very regular. These excrescences, which 
almost touch one another, vary in colour; they are reddish-brown, or golden, or 
of a dull crimson, or brownish, but always longitudinally marked with two or 
three bands of a deeper colour. But what only varies rarely is that there are six 
vertical rows of tubercles of a pretty bluish-grey, lined with brown. The disc, of 
a delicate yellow, bears three rows of short tentacles, and tinted with the same 
colour. The margin of the mouth is orange. 
‘This Actinian is a wanderer, or adheres only very slightly to the ground, for 
each tide throws up millions on the shore. Those we found at King George’s 
Port (Port du Roi-Georges) were only about two inches in diameter; but further 
away, at Western, in Bass’ Straits, individuals had the size of two fists.” 
. Body-wall—The ectoderm (which has almost entirely disappeared in the 
specimens) is of medium thickness, and covered witha delicate cuticle, in which is 
imbedded foreign colourless particles. 
The mesoglea presents a granular appearance, due to the number of very 
small cells. Its inner border is much plaited for the endodermal muscle. 
The endoderm is thick and crowded with dark granules; the dark granules 
which occur so numerously in the endoderm are probably the remains of Zooxan- 
thelle. The muscle layer is well developed and slightly dendritic in section; it 
is especially well marked around the apertures communicating with the vesicles. 
The latter have the same structure as the body-wall. The mesoglcea is very thin. 
Sphincter muscle (Pl. 1x., fig. 1)—The sphincter muscle is elongated and 
diffuse, and extends vertically from the outermost tentacle to the uppermost 
vesicles. The muscle fibres are rather weak, and are disposed on mesogleal folds, 
which are sometimes complex. 
Tentacles (Pl. 1x., fig. 2).—Ectoderm thick. The muscle is very strongly 
developed, and has become mesoglceal in position. The mesoglcea is thick. The 
endoderm is thick and crowded with granules. The endodermal muscle is distinct. 
Disc.—No ectoderm is preserved. The mesoglcea is of medium thickness, and 
much plaited for the support of the endodermal muscle. Hndoderm thick and 
crowded with granules. 
@sophagus.—With twenty or more folds on each side. The ectodermal folds 
are supported by mesoglceal extensions. Ectoderm, with elongated mesoglea, 
thin. Endoderm as in disc. 
Mesenteries (Pl. 1x., fig. 3)—Very numerous. They appear to be arranged in 
the ordinary Hexactinian manner, and to consist of 5 cycles (6+6+ 12 +24+448). 
No directive mesenteries were observed. 
2B2 
