654 



Haddon and Shackleton — A Revision of the British Actinice. 



SYNOPSIS OF BRITISH SPECIES OF PAEAZOANTHUS. 



(external chabacters.) 



Coenenchyme thin, band-like, or inconsiderable ; capitular ridges about 18, 

 prominent, granulated, ....... 



Coenenchyme thick, soft, expanded ; capitular ridges about 21 ; not so prominent 

 as in former, ........ 



P. anguicoma. 

 P. dixoni. 



(anatomical characters.) 



Mesenteries project only a short distance from the body-wall into the ccelenteron ; 



eudoderm of moderate thickness, uniform ; incrustations numerous, . P. anguicoma. 



Mesenteries project a considerable distance from the body-wall into the ccelen- 

 teron ; endoderm forming very thick ridges between every two mesenteries ; 

 incrustations few, ........ P. dixoni. 



The following species is inserted for comparison with the above : — 



Coenenchyme thin, band-like or irregular expansions ; capitular ridges 13-15, not 

 very prominent, ........ 



Mesenteries much as in P. anguicoma : endoderm very thin and uniform ; incrus- 

 tations not very numerous, chiefly spicular, .... 



P. axinellm 

 (Mediterranean). 



Parazoanthus axinellae (Schmidt). 

 Type species. — (Not British.) 

 (PI. Lix., fig. 8; PI. Lx., figs. 6, 7.) 



Palythoa axinella : 



Schmidt, 1862, Spongien des Adriatischen Meeres, p. 61, pi. vi., figs. 2, 3. Gray, 1867, Proc. 

 Zool. Soc, p. 238. Heller, 1868, Ber. k. zool., bot., Gesellsch., Wien, p. 21. Jourdan, 1880, 

 Ann. des. Sci. Nat. (6), x., p. 43. MiiUer, 1883, Morphologic Palythoa u. Zoanthus, p. 8. 

 Carus, 1884, Prod. Faun£e Medit., p. 76. 



Zoanthus axinellcb : 



Koch, 1880, Morph. Jahrb., vi., p. 359, pi. xvi., figs. 1-6. 



Palythoa (str. s.) axinellce : 



Andres, 1884, Le Attinie, p. 311, pi. x., fig. 7. 



Form. — Polyps obconical, coated with foreign particles ; capitular ridges, 

 13-15, not very distinct. Tentacles, 26—30 ; pointed with a very slight 



