138 J. E. DuERDEN — Jamaican Actiniaria : 



several of the forms to follow. From his jDaper just received, I find that Professor 

 Haddon and myself have independently come to the same conclusion with regard 

 to the degree of importance to be attached to these histological details. In the 

 same contribution Haddon discusses at some length the points at issue between 

 Carlgren's tribe Protanthe^ and the Peotactini.j; of M'^Murrich. 



Regarding it as a relic from the ancestral Scyphistoma, Haddon (p. 411) 

 considers that the ectodermal columnar and stomodseal musculature may persist 

 amongst the lowest, i.e. the least specialized, members of various groups. This 

 view of its significance is further sujiported by the fact that it is often associated 

 with a practically homogeneous mesogloea, and sometimes with the absence of the 

 " Flimmerstreifen " of the mesenterial filaments. Such is the case in Corynactis 

 and Ricordea, and partly so in Cerianthus, in each of which an ectodermal muscu- 

 lature occurs ; but in Phymauthus, and one or two others where the same struc- 

 ture is also developed, the mesogloea is fibrous and includes numerous cells. 



In a recent paper (1898), I have endeavoured to show that the combination of 

 external and anatomical features met with in several of the Stichodactylinse here 

 described, are such as are also characteristic of the Madreporaria. 



Sub-order. — Heterodactylin^, n. s.-o. 



Family. — Phymanthid^, Andres. 



ThalassianthincB, . . (pars), M. Edwards, 1857. 

 PhyllactinicB, . . (pars), Klunzinger, 1877. 



PhymanthidoB, . . Andres, 1883 ; M'Murrich, 1889 ; Kwietniewski, 

 1898 ; Haddon, 1898. 



Stichodactylinse, in which the tentacles are of two kinds : marginal tentacles 

 arranged in several alternating entacmseous cycles, laterally tuberculiferous, or 

 frondose ; inner tentacles radially or irregularly arranged, ver}' small, tubercular 

 or papilliform. 



Genus.— PHYMANTHUS, Milne Edwards.* 



Actinia, . . . (pars), Lesueur, 1817. 



Actinodendron, . . (pars), Ehrenberg, 1834. 



Phjmanthus, . . Milne Edwards, 1857 ; Klunzinger, 1877 ; Andres, 



1883 ; M'Murrich, 1889 ; Kwietniewski, 1898 ; 



Haddon, 1898. 



* While this contribution was going through the press I received from Prof. A. E. Verrill a copy of 

 his paper : " Descriptions of new American Actinians, with critical notes on other species, I." Amer. 

 Joum. Science, vol. vi., 1898, pp. 493-498. In connexion with the genus of the species here referred 



