136 



Scientific Proceedings, Royal Dublin Society. 



1889. M'=MuEKicH, J. Piatfaie: 



" On tlie Occurrence of an Edwardsia Stage in the Pree- Swimming 

 Embryos of a Hexactinian." — Johns Hopkins University 

 Circulars, viii., No. 70, March. Baltimore. 



1889. Haddon, a. C. : ' 



" A Eevision of the British Actiniae. " Part i. — Trans. Eoy. Dublin 

 Soc, XV., ser. ii., June, p. 297. 



1890. Beneden, E. van : 



" Les Anthozoaires pelagiques recueillis par M. le Professeur 

 Hensen dans son Expedition du Plankton, i. Une Larve 

 voisine de la Larve de Semper." — Bull. Acad. roy. Belgique, 

 (3) XX., p. 55, pi. i. 



1891. Beneden, E. van: 



" Pecherches sur le Developpement des Arachnactis. Contribution 

 a la Morphologie de Cerianthides." — Archives de Biologic, 

 xr., p. 115, pis. iii.-v. 



EXPLANATION OF PLATE XI. 



ah. d. 



ect. 



end. 



end. r. 



m. 



m.f. 



Figures 

 1-7. 



1,2. 



3. 



4. 



5. 

 6.7. 



aboral disc, 

 ectoderm, 

 endoderm. 

 endodermal ridge, 

 mesentery, 

 mesenterial filament. 



ms. mesoglcea. 



n. ect. nervous layer of ectoderm. 



s. d. sulcar directives. 



si. d. sulcular directives. 



st. stomatodseum. 



%. zooxanthellge. 



External appearance of Larvae of Euphyllia. (Not drawn to scale.) 

 Eirst stage of free-swimming larvae. 

 Pyriform appearance of a floating larva. 

 Aboral aspect of a cake-shaped larva. 

 Another view of the same. 

 Appearance of larvae on becoming sessile. 

 Transverse section through the middle of the body. Zeiss 



3 



2 

 A' 



9. Portion of a similar section. Zeiss 

 10 



B' 



Vertical section of a larva corresponding to fig. 7. Zeiss — . 



