FORSTER COOPER—ANTIPATHARTA. 315 
branches, which divide and subdivide in an irregular dichotomous manner. The branches 
are straight and grow sharply upwards, the whole colony being of the ‘‘ broom” type 
of growth. 
Some of the sub-branches become confluent, and fuse with one another as well as with 
the main stem. 
The polyps on the smaller branches are arranged in regular lines, of which there are 
usually four round the circumference. Young intercalated polyps, however, very 
frequently break up the regularity of this arrangement. On the larger stems they are 
less regular, and on the lower part of the main stems and on the basal part they are 
absent. 
The polyps are normal in type, 2°5 mm. in diameter, and placed close together, about 
four to the centimetre. Two varieties occurred in about equal proportions—the one with 
white polyps, the other having them of a brilliant sulphur-yellow colour. In all other 
respects the colonies are precisely the same. 
The spines are very regular in size, being 0°2 mm. in length. In shape they are 
triangular, compressed, and fairly sharp, with the lower border longer than the upper, 
so that they are hooked upwards. The arrangement is either in straight lines or steep 
spirals, the latter condition being due to the twisting of the axis itself—a feature which 
occurs irregularly. 
On the larger stems they become more numerous, and the regularity of arrangement 
is masked. On the base they are worn away, and the corallum is smooth and 
shiny. 
Locality. Cargados Carajos, 30 fathoms. 
43 * 
