NEW SPECIES OF EDWAEDSIA FROM NEW GUINEA. 529 



much more specialised in this respect than the Edwardsise. The out- 

 standing feature, however, in the growth of the Edwardsise is that, after 

 the eight-rayed stage is reached, the mesenteries continue to be formed 

 in couples of singles and not in couples of jMirs, as in the Dodecactiniaria 

 and Zoanthinaria. In short, the mode of development characteristic of 

 the first four couples formed in the larvae of Zoanthese, Actinians, and 

 Madreporaria is continued to the end in Edwardsidae. This mode of deve- 

 lopment is universally regarded as primitive. The Edwardsidse, then, retain 

 the primitive mode of development and growth throughout their existence 

 and for this reason must be regarded as a separate branch of a primitive 

 stock in which only four couples * of mesenteries were present. From 

 this stock the Edwardsiaria, the Zoanthinaria, and the Dodecactiniaria have 

 been derived. 



List of the Worl's referred to in the Text. 



1. Andres, A. Intoi-no all' Edioardsia claparedii, Pane. Mitth. aus d. 



Zool. Stat, zu Neapel, ii. 1880, p. 123. 



2. • Fauna u. Flora des Golfes von Neapel. IX. Actinien. 1884. 



Pp. 89. 



3. Beneden, Ed. van. Die Anthozoen der Plankton-Expedition, Ergebn. 



der Plankton-Expedition der Humboldt-Stiftung, ii. K. e, 1897. 



4. Bourne, G. G. Lankester's Treatise on Zoology. Pt. II. Anthozoa. 



1900. 



5. BovERi, Th. Ueber Entwickelung und Verwandtschaftsbeziehungen 



der Aktinien. Zeitschr. f. Wiss. Zool. xhx. 1890, p. 461. 



6. Dixon, G.Y. Notes on Two Irish Specimens of Edyardsia timida, Quatr. 



Proc. Roy. Dublin Soc. n. s., v. 1886, p. 100. 



7. Carlgrbn, 0. Studien liber nordische Actinien. KongL Svenska 



Vetensk.-Akad. Handlingar, xxv. 1893. 



8. Hamburger MagalhaensischeSammelreise: Zoantharien. Hamburg, 



1898. 



9. Bronn's Thierreich. Anthozoa. 4, 5, & 6 Lief. 1908. 



10. Faurot, L. Etudes sur les Actinies. Arch, de Zool. Exp. et Gen. (3) 



iii. 1895. 



11. GossE, p. H. Actinologia Britannica, 1860, p. 254. 



* Throughout this paper I have used the terms " couple " and " pair " in the sense 

 indicated hy Faurot. In my article on the Anthozoa in Lanliester's ' Treatise on Zoolog-y ' 

 I use the same terms, but in exactly the opposite sense to Faurot. My article, though 

 published in 1900, was written in 1895, the same year in which Faurot's paper appeared. 

 His use of the terms has priority over mine and should be adopted. 



LINN. JOURN. ZOOLOGY, VOL. XXXII. 42 



