Happon anp Durrpen—Some Actiniaria from Australia and other Districts. 143 
may be connected, but the present species is the first in which the presence of the 
coenosare is undoubted. 
The history of the genus will be found on page 687 of the above Report. 
Hitherto, only the following four species have been recognised as belonging to 
the genus :—G. ruse’, Duch. & Mich., from St. Thomas (1889); G. isolata, M*Murr., 
from the Bahamas (1889a) ; G. Macmurrichi, Hadd. & Shackl., and G@. mutuki, 
Hadd. & Shackl., from Torres Straits. We now add a description of a new 
species, G. Canariensis, from the Canary Islands. 
Gemmaria Canariensis, n. sp. 
(Pl. vu, fig. 2.) 
Form.—The column is erect, rigid, and of about equal diameter throughout, 
except at the upper part of contracted specimens, which is swollen, and possesses 
about 24 radiating ridges. The ectoderm has almost entirely disappeared. 
Where present, it is coarse in appearance. The polyps rise from a thick, firm, 
continuous ccenosare. 
Colowr.—The true colour is removed by the alcohol in which the colonies are 
preserved. They are now of a dark purple tint, due to the pigment from an 
Aplysia placed in the same jar. his is largely removed on placing the specimens 
in acid. 
Dimensions.—Height, 13 mm.; average diameter of column, 3 mm.; greatest 
diameter capitular region, 5 mm. 
Locality —Canary Islands. Two colonies, each with three or four connected 
polyps. 
The specimens were kindly placed at our disposal by Prof. W. A. Herdman, of 
University College, Liverpool. 
Body-wall (Pl. vut., fig. 4).—In the two specimens cut for longitudinal and 
transverse sections, the ectoderm of the column is almost absent. Where, how- 
ever, traces do occur, it is continuous, of considerable diameter, and contains 
numerous zooxanthelle. A thin cuticle is present, containing frustules of 
diatoms. 
The incrustations consist mostly of siliceous and calcareous sand-grains and 
sponge spicules, but they are all limited to the outermost part of the mesogloa 
and to the ectoderm. The incrustations give the surface of the column a 
roughened appearance where the ectoderm is wanting. 
The mesogloea is moderately thick in the upper part of the column, and 
increases considerably towards the base. It is crowded with cell-islets of variable 
size. ‘The larger of these are mainly limited to the central zone of the mesogleea. 
