Part II. — Stichodactylince and Zoanthece. 187 



gland cells, both in the ectoderm and endoderm is noteworthy; and also the very- 

 large, oval cnidocysts in the knobbed tentacles, stomodaeal ectoderm, and mesen- 

 terial filaments. The mesogloea is an excejitionally homogeneous layer, and the 

 retractor muscle of the mesenteries is arranged on only slight mesogloeal folds, 

 never becoming circumscribed. Undoubtedly one of the most important ana- 

 tomical features is the absence from the mesenterial filaments of any lateral 

 lobes bearing the Flimmerstreif. 



Tribe.— ZOANTHE^, R. Hertwig, 1882. 



Family. — Zoanthid^, Dana, 1846. 



Sub-family. — Maceocnemin^, Haddon and Shackleton, 1891. 



For the definitions of the Tribe, Family, and Sub-family, the first instalment 

 of this series should be consulted, or better, the original papers of Haddon and 

 Shackleton (1891, 1891 «). 



Genus.— PARAZOANTHUS, Haddon and Shackleton, 1891. 



Macrocnemic Zoantheae, with a difPuse endodermal sphincter muscle. The 

 body-wall is incrusted. The ectoderm is continuous. Encircling sinus as well as 

 ectodermal canals, lacunse, and cell-islets in the mesogloea. Dioecious. Polyps 

 connected by thin coenenchyme, rarely distinct. 



The characters of greatest generic importance are the macrocnemic arrano-e- 

 ment of the mesenteries, a feature shared with the genus Epizoanthus, and the 

 presence of a diffuse endodermal sphincter muscle. 



In their "Review of the British Actinire," Haddon and Shackleton assign to 

 the genus three European forms ; P. axinellce (Schmidt), P. anguicomus (Norm.), 

 and P. Dizoni, n. sp., and, in their Report on the Zoantheae collected by Professor 

 Haddon in Torres Straits, make an addition of two new species, P. dichroicus and 

 P. Douglasi. In the paper on Jamaican Zoantheae, I show that the Gemmaria 

 Siviftii, of Duchassaing and Michelotti (1860), must be transferred to Parazoauthus 

 and also advert to the fact that Carlgren (1895) has demonstrated that the supposed 

 Antipatharian genus Gerardia, Lac.-Duth, must probably be regarded as belono-ino- 

 to the same genus. Reviewing the Zoanthean genera in his latest paper, Haddon 

 (1898, p. 408) confirms Carlgren's statements with respect to this form, and 

 locates Gerardia between the genera Parazoanthus and Ejjizoanthus. 



Recent trawling in the Caribbean Sea has brought up from the Pedro Banks 

 distant about 50 miles south-west of Jamaica, a branching Hydroid over 100 cm. 

 in height, the trunk and main divisions of which are entirely incrusted with a 

 single Zoanthid colony. It bears a very close external resemblance to Parazoanthus 



