J. E. Durerpen—Jamaican Actiniaria: Part I.—Zoanthee. 333 
ZOANTHUS, Lamarck, 1801. 
Brachyenemic Zoanthez, with a double mesogloeal sphincter muscle. The 
body-wall is unincrusted; the ectoderm is usually discontinuous ; well-developed 
ectodermal canal system in the mesogleea. Moncecious or dicecious. Polyps 
connected by a thin lamellar ccoenenchyme, stolons, or, more rarely, free. 
The synonymy of the genus Zoanthus is given by most recent writers upon 
the Zoanthidee. 
The following are the references to the genus Mammillifera, which, as shown 
below, must be merged in Zoanthus : 
Mammillifera, : 2 : . Lesueur, 1817, p. 178. 
Mamillifera, . : : ‘ . Blainville, 1834, p. 329. 
Mammillifera, . ; ; . Ehrenberg, 1834, p. 46. 
Mamillifera, . : : : . Duchassaing, 1850, p. 11. 
Palythoa (pars.) . : : . Milne-Edwards, 1857, p. 301. 
Zoanthus, : : : . Gosse, 1860, p. 296. 
Mamillifera, . , : ; . Duchassaing and Michelotti, 1860, p. 327; 
1866, p. 136. 
Mammillifera, : : : . Verrill, 1869, p. 495. 
Mammilifera, ; : : . Hertwig, 1882, p. 111. 
Polythoa and Zoanthus (pars.), . Andres, 1883, pp. 306 and 323. 
Mammillifera, : : : . Erdmann, 1885. 
Mammitlifera, ‘ : : . Hertwig, 1888, p. 35. 
Mammillifera, : : : . M*Murrich, 1889, p. 117. 
Mammitlifera, ‘ : . Haddon and Shackleton, 1891, p. 630. 
Zoanthus, 2 ; : : . MeMurrich, 1896, p. 188. 
The distinction between the Zoanthez and other Actinie was first recognised 
by Cuvier in 1798, and the genus Zoantha first employed by Lamarck in 1801. 
Later, Cuvier (1817) restricted Zoanthus for Actinians occurring in groups ad- 
hering to a common base, which is sometimes broad and flat, and at other times 
a sort of creeping stem. In the same year, Lesueur (1817) separated, under the 
genus Mammillifera, those which have ‘A large cuticular expansion, serving 
as the base of numerous animals which, when contracted, assume the form of 
mamme.” This genus was received by Blainville (1834), Ehrenberg (1834), and 
Duchassaing (1850). Milne-Edwards (1857) united the included species under the 
genus Palythoa, established by Lamouroux (1816). Duchassaing and Michelotti 
(1860 and 1866) again separated the two genera, restricting Palythoa to the 
forms which have the integuments hardened by incrusting foreign matter. Gosse 
(1860) embraced, under Zoanthus, both the Palythoa of Lamouroux and the 
Mammillifera of Lesueur in addition to the other genera, all forms spreading 
