32 



ZOANTHARIA 



poh'ps according to Danielssen are "almost piriform." The small contracted polyps with quite 

 retracted tentacles are somewhat narrower in the proximal than in the distal part, which is somewhat 

 rounded. The expanded polyp was narrowest a little above the base, then gradually becoming wider 

 and reaching its greatest breadth some way below the tentacles, afterwards tapering a little towards 

 the base of the tentacles. The distal part is provided witli capitular furrows, which Danielssen 

 states to be 12 in number. This is too few, as far as I can see. The ridges and furrows are certainly 

 not so distinct in the preserved polyp, but I have found 16 — 18. The polyps are incrusted with sand- 

 grains, especially in the proximal part and in the ccenenchyme. 



The number of tentacles probably agrees with the number of mesenteries. 



The oesophagus has a very distinct siphonoglyphe. 



Anatomical description. The ectoderm of the body-wall is fairly thin, considerably thinner 

 than in E. glacialis , continuous and provided with a thin cuticle. In the ectoderm are fairly many 

 spirocysts (normal shape?) and large nematocysts with greatly twisted thread. The latter have a length 

 of 29—31 n and a breadth of \2 (i (the lower part being broader than the upper). Small cells occur 

 in great numbers, but no lacunae or groups of cells seem to be present in the mesoglcea, at least not 

 in the distal part (PL 5, fig. 6). The incrustation is fairly strong and consists of comparatively large 

 sand-grains, here and there a sponge-needle and exceptionally foraminifera. The entoderm is well- 

 developed and thicker than the ectoderm. 



The sphincter is mesoglccal but not so strong as in the other Epizoanthus-species examined 

 by me (PI. 3, fig. 4). In the distal part the meshes are considerably larger than in the proximal and 

 extend horizontally, i. e. in the direction from the ectoderm to the entoderm. The bridges of connective 

 tissue between the muscle-meshes were broad. 



The tentacles have the usual structure. The ectoderm is very high with numerous large 

 spirocysts; further, it contains the same kind of large nematocysts as occur in the body-wall and typical 

 thick-walled capsules (length 17^0). The mesoglcea is thin, the longitudinal musculature moderately 

 developed. 



The ectoderm of the oesophagus is fairly thick and contains large capsules, almost of the same 

 kind and size as those in the body-wall, besides not a few typical thick-walled capsules (length 24— 26/() 

 The mesoglcea is thin, being however considerably thickened in the siphonoglyphe. 



The .single specimen examined by me had 32 regularly arranged mesenteries. Danielssen's 

 statements on tliis matter cannot be correct, as it is quite evident from his figure, that he has not 

 seen the macro-type arrangement but has supposed the macro and micro-mesenteries to be alternating 

 everywhere. The mesoglcea of the macro-mesenteries is fairly thick, the micro-mesenteries rather long 

 but narrow and not much developed. The musculature is comparatively weak. 



The filaments seem to have the usual structure. The glandular tract contains the same kind 

 of nematocysts as occur in the cesophagus. The thick-walled capstiles may sometimes be a little 

 smaller (22—24//). 



The sexual organs were not developed in the poI\p closely examined by me. 



