J. E. Duerpen—Jamaican Actiniaria: Part I.—Zoanthee. 365 
Palythoa caribeea, Ducuassainc and MIcHELorTri. 
(PI. xvu. 4, fig. 9.) 
Palythoa caribeorum,  . . Duchassaing and Michelotti, 1860, p. 329. 
Palythoa caribea, . ; .  Duchassaing and Michelotti, 1866, p. 141, Pl. vi., 
fice Fie 
Polythoa (Monothoa) caraibeorum, Andres, 1883, p. 322. 
Form.—Polyps smooth, rigid, cylindrical, closely associated and arranged in 
an irregular manner, usually free from the ccenenchyme for a short distance, 
free portion rounded or conical in retraction; in very strong retraction, the 
upper surface of the colony may be nearly flat; no wrinklings in specimens 
preserved in formalin. Capitular ridges and furrows variable, usually from 14 to 
17. The following numbers counted on two colonies will indicate the amount of 
this variation :— 
A.—15, 14, 16, 15, 14, 16, 14, 16, 15, 15, 15, 15, 14, 15, 15, 15, 15, 15, 15, 16, 15, 14, 
16, 16, 17, 16, 17, 15, 14, 17, 15, 15. 
B.—14, 18, 16, 14, 17, 15, 17, 17, 15, 17, 14, 15, 15, 14, 15, 14, 16, 15, 16, 16, 16, 16, 
16, 17, 17. 
Tentacles dicyclic, smooth, pellucid, very short, acuminate, slightly entacmzous, 
inner row opposite capitular ridges, overhanging in full extension, vary from 28 
to 34 in number. Disc considerably depressed in partial extension, overhanging 
in full extension, cup-shaped or saucer-shaped, according to amount of extension ; 
divisible into two portions: an outer, thin, transparent, non-incrusted, circular 
area with rounded ridges and furrows corresponding to the number of tentacles, 
and a dome-shaped central portion, with a few minute incrustations, and bearing 
the slit-like mouth at the apex. 
The polyps are arranged very closely, and the amount of ccenenchyme con- 
necting the individuals is thin. At the periphery of the colonies, the outlines of 
the different marginal polyps are clearly indicated. New individuals appear to 
arise between previously existing ones. ‘The colonies are usually very extensive, 
irregular in outline, and often incrust very uneven surfaces, the height of the 
polyps varying accordingly, so as to produce a regular undulating surface above. 
Colour.—In the living condition, a pale yellow or cream colour, or sometimes 
‘brown, white when the ectoderm is rubbed off, lips white. In specimens preserved 
in formalin a curious change is effected. Nearly the whole of the upper surface 
of the colony may become a brick-red colour, The capitular ridges, however, for 
