80 OLWEN M. REES. 



all its mesenteries fully developed and has a deep and well-defined 

 siphonoglyphe ; also the distribution of nematocysts is different in the 

 two forms. Eloactis possesses twenty highly specialized tentacles, all 

 well armed with nematocysts, and these are present only on the tentacles, 

 especially on their ovate heads. H. pilatvs does not possess such highly 

 specialized tentacles ; they are more numerous, and nematocysts are 

 present on the disk and body wall as well as on the tentacles. Thus 

 the tentacles are not so well adapted as feeding and defensive organs, 

 and the division of labour is not so complete as in E. mazeli. 



Peachia is probably still more advanced : — 



It has a single deep siphonoglyphe like E. mazeli, but the longi- 

 tudinal retractors of the perfect mesenteries of Peachia are more elon- 

 gated (in section), and there is a better developed system of musculature 

 than in E. mazeli. 



Eloactis mazeli is therefore an elongated anemone, with twenty highly 

 specialized tentacles, ten pairs of perfect and fully-developed mesen- 

 teries, and a deep and well-defined siphonoglyphe, and is probably 

 intermediate in position between Halcurias and Peachia. 



BIBLIOGRAPHY. 



1. JouRDAN, E. Recherches zoologiques et histologiques sur les Zoanthaires 



du Golfe de Marseille, 1880. 



2. Andres, A. Le Attinie, Vol. I. Fauna und Flora des Golfes von Neapel. 



Leipzig, 1884. 



3. McMuRRiCH, J.P. Scientific Results of Explorations of the United States 



Commission Steamer Albatross, 1887-1888. Report on Actiniae. 



4. Haddon, a. C. a Revision of the British Actiniae. Trans. Roy. Dublin 



Soc, Ser. II, Vol. IV, 1888-1892. 



5. Lankester, E. Ray. A Treatise on Zoology, Part II. 



6. Delage, Y., et Herouard, E. Zoologie Concrete, Tome II, 2 A. 



