CERIANTHARIA. 



jections between the mesenteries. As they are not always clearly shewn, it is possible that they are 

 prodnced by contraction. The endoderni is provided with numerous mucus cells and granular 

 gland cells. 



The ectoderm of the tentacles and oral disc contains numerous thin-walled nematocysts, spiro- 

 cysts, and numerous nematocysts with much-coiled spiral thread, also a kind of thick-walled granu- 

 lated capsules with long basal part of spiral thread (length 53— 65;/) and lastly thick-walled nemato- 

 cysts but considerably smaller than the foregoing. The ectoderm of the tentacles is half the thickness 

 of that of the column but considerably thicker than the mesogloea. The mesogloea is comparatively 

 thick with higher folds on the inner side of the tentacles than on the outer, for which reason the 

 longitudinal musculature is more developed on the inner side of the tentacles. Those of the radial 

 musculature are strongly marked in the oral disc and the folds somewhat lower than the ectoderm. 

 The endoderm of the oral disc on the other hand is thinner than the height of the muscle folds. 

 (PI- I, Fig. 3). 



Stomatodaeum : The ectoderm is very high and folded and supported even in the upper por- 

 tion by a mesogloeal process of triangular cross section. The ectoderm is everywhere of the same struc- 

 ture with the exception of the very lowest part. The nematocysts with nuich-coiled spiral thread are 

 numerous and about 46 — 53;^ long and 5« broad. In the aboral part are found also spirocysts and 

 thick-walled nematocysts of about the length of 36;^. As usual the ectoderm contains numerous 

 mucus and albumen gland cells which in the upper portion of the stomatodaeum are scattered about, 

 but in the lowest portion like the nematocysts are clustered at the crest of the fold, whilst the furrows 

 between the folds and the sides of these chiefly consist of supporting cells, an arrangement which 

 is spoken of more fully under C. lloydii. The mesogloeal folds are in the lowest part narrow in 

 transverse section and long as usual with this species. The ectodermal musculature is ver}' feeble, 

 especially in the lowest portion of all where only scattered muscle cells appear; on the crests of the 

 mesogloeal folds in the most central part of the stomatodaeum the muscle lamella shews a tendency 

 to be enclosed in the mesogloea, as here and there the muscle fibres are found enclosed in the meso- 

 gloea. The mesogloea contains only a few scattered cells. 



The ectoderm of the siphonoglyph is high, not folded, with numerous homogeneous gland 

 cells but with sparsely scattered nematocysts. The longitudinal musculature is very feeble. The 

 mesogloea is thin in the middle but much thickened near the stomatodaeum. I have not observed 

 any ciliated tracts on the hyposulcus, at least none are found in the aboral portion of the hyposulcus. 

 A transverse section of a hemisulcus (PI. i, Fig. 4) is very nuich like a transverse section of a median 

 streak of the filament. The high ectoderm contains very numerous gland cells and more sparsely 

 scattered nematocysts. These chiefly consist of thin-walled nematoc\sts but nematocysts with much- 

 coiled threads too are found, as also thickwalled ones of the same dimensions as in the stomatodaeum. 

 The longitudinal musculatiire in the hemisulci is feeble but plain. 



Mesenteries: (Text-figure i). I have counted the number of the mesenteries in 2 specimens. In 

 ex. E were found 38 mesenteries of the ist cycle, in ex. A I observed on the leftside 17 large mesen- 

 teries of the ist cycle which reached to the aboral portion of the animal, and 2 lesser ones, which 

 reached to the middle of the space between the aboral border of the stomatodaeum and the aboral 



