J. E. Durrprn—Jamaican Actiniaria: Part I.—Zoanthee. SHA) 
macrocnemic arrangement, occur in one specimen, and are all very thin except 
near their origin and where fertile ; the imperfect are very short; the paricto- 
basilar muscle is developed along each side; no basal canals, or only traces of 
them, are present. The mesenterial muscles are seen on slight plaitings; pigment 
granules occur in groups on the endoderm. The digestive endoderm is thick, and 
large oval nematocysts are embedded init, along with groups of pigment granules. 
The imperfect mesenteries have the muscle fibres extending all round. In the 
distal region, just below the cesophagus, the mesogloea at the origin of the mesen- 
teries is rectangular, but proximally it becomes goblet-shaped, the part produced 
beyond in perfect mesenteries being extremely thin. Proximally the mesenteries 
are branched. 
Gonads (Pl. xx., fig. 4).—Spermaria apparently enclosed in endoderm were 
met with in abundance in two specimens. 
This species is most closely allied in outward appearance to the well known 
European Epizoanthus Couchii (Johnston), Hadd. and Shackl. Obvious differences 
occur in the number and form of the eapitular denticulations, the Antillean 
representative having fifteen, sixteen, or twenty-one, truncated at their free edge ; 
while the older species has twelve or fourteen triangular teeth. The tentacles 
differ in a corresponding manner. Histological characters indicate further dis- 
tinctions. It is readily separated from the seven other species examined by the 
two authors mentioned above, and also from the ‘‘ Challenger” 
American forms it appears to bear a close relation to the incompletely described 
Epizoanthus humilis, Verr. (1869), from Panama. 
species. Of 
Parazoanthus, Haddon and Shackleton, 1891. 
Macrocnemic Zoanthez, with a diffuse endodermal sphincter muscle. The 
body-wall is incrusted. The ectoderm is continuous. Encircling sinus as well as 
ectodermal canals, lacune, and cell-islets in the mesoglea. Diccious. Polyps 
connected by thin coenenchyme. 
This genus, with the above definition, was established by Haddon and 
Shackleton (1891, p. 653), to include macrocnemic Zoanthez with a diffuse endo- 
dermal muscle, forms which previously had been referred by Hertwig and 
Erdmann (1888, p. 35) to the genus Palythoa. The authors recognize five species 
examined by them, and two described by Hertwig and Erdmann. The combi- 
nation of anatomical characters renders it a well-defined genus. 
Carlgren (1895) has shown that the genus Gerardia, Lac.-Duth., formerly in- 
cluded, with some hesitation, amongst the Antipatharia, is closely allied to the 
present genus, differing only in the presence of a strongly developed horny 
skeleton. 
8K2 
