158 J. E. Durrpen—Jamaican Actiniaria: 
tentacles have a green, blue, or brown stem, and the knob green or yellowish- 
green, or white in one variety. Often there is a marked difference in colour 
between the dicyclic marginal tentacles and the inner radiating group. The disc 
is richly coloured; green or blue along the radii, but towards the inner naked 
area, dark purplish brown. The peristome is bright green; the walls of the 
stomodzeum are white or light green. 
Specimens were procured at Port Antonio in which the tip of the dise 
tentacles was coloured bright orange red. ‘They were associated with other 
polyps of the more usual colours, to which they presented a marked contvrast. 
Duchassaing and Michelotti also refer to a similar variety. 
Around the Port Royal Cays two other slight colour varieties occur, also in 
close association ; in one green and purplish brown predominate, and in the other 
light green or grey. They are readily distinguishable when seen @ siéw in 
patches of considerable size, the members of any one patch being alike, much in 
the same way as has often been described for groups of Corynactis. 
The dimensions are very variable. ‘The height of the column in extension 
may vary from 1:1 cm. to 2°7 cm., while the diameter may be 1-7 cm. The 
greater length of the disc of a specimen with four mouths, and also of one with a 
single mouth, was 3°5 em.; another bearing two apertures was 5:5 cm. in exten- 
sion, with a diameter of 3°8 em., and a length of 4 cm. in contraction. 
The length of the marginal tentacles of the inner cycle is 0°5 em. 
ANATOMY AND HIsTouoey. 
In endeavouring to remove the animal from the rock to which it is attached, 
the base often becomes partly destroyed. Where perfect, however, the basal 
ectoderm is seen to be formed of elongated columnar cells, which are mostly large, 
unicellular glands, aggregated, along with the narrow supporting cells, around fine 
mesogloeal processes. A thick cuticular membrane, apparently formed of coagu- 
lated mucus, is present in some specimens between the ectoderm and the foreign 
object to which the polyp is attached. 
The mesogloea of the base, like that throughout the whole polyp, is a thin 
clear layer, and comparatively few cells are included within it. It stains slightly 
with borax carmine. In regard to the abundance of the mesoglceal cells, the 
species is intermediate between their practical absence in Corynactis and the great 
quantity in most Actiniz. In the upper part of the polyp the layer is almost 
completely homogeneous, an included cell occurring but rarely. In these places 
it is indistinguishable from the mesogloea of Corynactis and the Madreporaria. 
The endoderm of the base presents no important characteristics, and is practi- 
cally devoid of zooxanthellee. 
