Happon—The Actiniaria of Torres Straits. 405 
Isaurus asymmetricus, H. & S. 
Isaurus asymmetricus, Hadd. and Shackl., 1891; Trans. R. D. 8S. (2) 1Vv., p. 684; 
Pl. wx1., figs. 7-9; Pl. uxt, fig. 4; Pl. uxtr., figs. 4-6; Pl. ixiv., fig. 9. 
Form.—Body elongated ; upper portion of column with usually four, sometimes 
more, rather irregular rows of tubercles, arranged in such a manner that there is a 
longitudinal area free from them; tubercles rarely absent; the smooth side is 
somewhat shorter than the tuberculated, so that the body bends over to the former. 
The contracted capitulum exhibits radiating furrows. The polyps grow either 
singly or in small clusters. 
Colour.—Whitish below, passing ito brownish above; the darker portion 
variously mottled with cream, or greenish cream, and occasionally diversified 
with darker spots; tubercles somewhat pinkish. 
Dimensions.—Average size of retracted specimens, 45 mm. in height; greatest 
diameter, 7 mm. 
Locality.—On reefs and between channels. 
GEMMARIA, Duch. and Mich., 1860. 
Brachyenemic Zoanthez, with mesogloeal sphincter muscle; solitary, or 
connected by ccenosare ; the body-wall incrusted with grains of sand and spicules ; 
the ectoderm usually discontinuous, but may be continuous. Lacunz and cell- 
islets are found in mesoglea. Dicecious. 
Gemmaria Macmurrichi, H. & S. 
Gemmaria Macmurrichi, Hadd. and Shackl., 1891; Trans. R. D.S. (2) 1v., p. 688 ; 
Pimms dc. tl: Pie nx, te 7. 
Form.—Erect, rigid; upper portion of contracted specimen with minute 
radiating corrugations. 
Colour.—Sandy. 
Dimensions. —Height, 13mm. (in spirit); diameter, 2—3°5 mm. 
Locality —Channel between Murray Islands, 20 faths. 
Ectoderm discontinuous, no zooxanthelle. 
Gemmaria Mutuki, H. & S. 
Gemmaria Mutuki, Hadd. and Shackl., 1891; Trans. R. D.S. (2) 1v., p. 689; 
Pl. ix1., fig. 10; fig. 1, p. 690. 
Form.—Nearly cylindrical; upper portion of retracted specimens with a large 
number (24—30) of fine radial ridges, which are continued some way down the 
