372 J. E. Durrpen—Jamaican Actiniaria: Part I.—-Zoanthee. 
Parazoanthus Swiftii (Duchassaing and Michelotti). 
(Ely xvi. Anis tle) 
Gemmaria Swift, . . . Duchassaing and Michelotti, 1860, p. 331, pl. viii., 
figs. 17, 18: 1866, p. 188. 
Polythoa (str. s.) avinelle, Andres, 1883, p. 311, pl. x., fig. 7. 
Form.—Polyps very short, cylindrical, mammiform in retraction, erect, firm, 
smooth, rising from small band-like branching patches of ccenenchyme incrusting 
the surface of a sponge; sometimes the polyps are arranged in a single linear 
series, at other times the coenenchyme is expanded, and two or three individuals 
may occur abreast. Capitulum with twelve serrations at the apex. In partial 
retraction these appear as so many wedge-shaped ridges, with intervening 
furrows, around a central orifice; in full retraction the capitular ridges are 
scarcely visible, and the polyps are rounded above. 
Tentacles minute, entacmeeous, acuminate, dicyclic, twelve in each row, the 
outer alternating with the serrations, overhanging in extension. Dise concave, 
transparent, with mesenteries showing through; mouth slit-like and capable of 
considerable eversion; lips crenate; cesophagus shows longitudinal mesenterial 
lines ; oral cone may be considerably elevated. The usual condition of the polyps 
appears to be that of retraction. 
The ccenenchyme is smooth, thin, in irregularly shaped meandering ribbons 
or patches firmly incrusting and partially embedded in the sponge. 
Colour.—Coenenchyme and column-wall are a bright orange yellow, lighter 
on the upper part of the column; tentacles are pale yellow; disc a darker, and 
lips a bright yellow. The parts are sand-coloured where the ectoderm is rubbed 
off. The bright orange colour gives to the colonies a marked contrast with the 
dark green sponge. 
Dimensions.—Height of polyps above the coenenchyme varies from 0°15 em. 
to 0'3 cm. ; diameter of expanded dise 0:4 cm. ; diameter of column in contrac- 
tion 0:2 cm. 
Locality.x— Jamaica: Obtained growing in small colonies on a large, erect, 
blackish-green, branching sponge collected in water of about two fathoms around 
Rackum Cay; also from the shallow waters S. W. of Lime Cay, living on the same 
species of sponge. 
Range.—St. Thomas (Duchassaing and Michelotti). 
Column-wall (Pl. xx., fig. 5)—The column-wall is very thick. The cuticle 
