406 Havpon—The Actiniaria of Torres Straits. 
column ; lower portion of column wrinkled in spirit specimens. Basal gemmation 
occurs. 
Colour.—Greyish white in spirit. 
Dimensions (in spirit).—Height, 10-12 mm. ; average diameter, 4°5 mm. 
Locality. —Mabuiag. 
Kctoderm continuous, zooxanthelle present. 
PALYTHOA, Lamouroux, 1816. 
Brachyenemic Zoanthez with a single mesogloeal sphincter muscle. The body 
wall is densely incrusted. The ectoderm is continuous (?); the mesoglcea contains 
numerous lacune, and occasionally canals. Dicecious. Polyps immersed in a 
thick ccenosare, which forms a massive expansion. 
Palythoa Howesii, H. & S. 
Palythoa Howesti, Hadd. and Shackl., 1891; Trans. R. D. 8S. (2) 1v., p. 693; 
Pip uxt, fio. 03 Pl rx, io... 
Form.—Polyps scarcely projecting above the surface of the ccenosare when 
contracted, and then, i most cases, only one side is prominent. Ccenosare 
thick, incrusting; the polyps are arranged in indefinite, roughly parallel rows; 
owing to the partial immersion of the polyps, the prominent portion of contiguous 
polyps have a tendency to form zigzag lines; the whole surface is very rigid and 
tough. 
Colour.—Sandy. 
Dimensions.—Average diameter of polyps 7 mm. 
Locality.—F ringing reef, Thursday Island. 
Palythoa Kochii, H. & S. 
Palythoa Kochi, Hadd. and Shackl., 1891; Trans. R. D.S. (2) 1v., p. 694; Pl. uxt. 
fig, 12; Pl. uxm., fig. 9: 
Form.—Polyps projecting slightly above the surface of the ccenosarec in 
contraction; ccenosare incrusting, of moderate thickness. Polyps so crowded 
as to usually have a polygonal contour; twenty capitular ridges and furrows; 
tentacles forty in number. 
Colour.—Ceenosare finely speckled buff and cream; disk very finely dotted 
with brown and opaque white; capitular ridges white. 
Dimensions.—Diameter of polyps about 5 mm. 
Locality.—F ringing reefs, Thursday Island, and Mabuiag. 
