55 



ginning of a branch. On the piece of stem delineated fig. 22 there was such a side-process, 

 issuing from the 2 n ? calcareous joint, already connected with a horny joint, and the latter 

 again with another short calcareous joint, being thus clearly a branch; and on the polyp- 

 bearing piece delineated fig. 5, it was properly only the lowest of the 2 large side-branches 

 which issued directly from the horny joint, while the other took its origin from the next 

 calcareous joint near the base. 



The so-called bark or the polyp-bearing fleshy envelope (csenenchym) begins (in the 

 entire specimens examined) first to be visible about in the middle of the length of the stem, 

 although really it encloses also the lower sterile part in the shape of an extremely thin mem- 

 brane. It is whitish, or rather yellowish transparent, so that the axis is clearly seen through 

 it, (see fig. '8) and full of vitreous spiculse. Its width is in the fresh state about twice the 

 thickness of the axis, and sometimes even more. 



The polyps, which stand out from the stem usually obliquely upwards and outwards, 

 are situated at some distance from each other, and apparently alternating on both sides of 

 the stem; but on closer examination they are found to be placed round about the stem, and 

 thus arranged spirally along the same. Between 2 horny joints there are usually found 5 10 

 polyps. These are of various sizes; as between those fully developed there are often found 

 very small budding polyps. The 'largest are when extended (see fig. 8) about 3 times as 

 long as the stem is thick (in the young specimens examined), or about 2 Mm. long; broadly 

 cylindrical, about twice as long as they are broad; when contracted about half as long, and 

 nearly globular or shortly cylindrical with rounded extremities. The mouth is surrounded by 

 8 tentacles, which are nearly as long as the body, conically elongated, or thickest at the 

 base gradually tapering towards the extremity, and on each side furnished with a series of 

 about 12 projecting conically pointed pinnules. The short and wide cylindrical gullet, or so- 

 called stomachal canal, shines through the skin of the polyp with its orange-yellow color, and 

 extends from the mouth about half way down the body, where the 8 septa or radial lamellae 

 also shine distinctly through as radial diverging orange-yellow sinuous stripes. The spiculse 

 in the polyp's body lie very closely packed together in the skin, and mostly in the direction 

 of the longitudinal axis of the body. They often project with their points somewhat above 

 the surface of the skin. Some of them, namely in the exterior part of the body, are as long 

 as half the body and even longer, and project with their points over the skin at, or between 

 the bases of the tentacles. Also on the exterior side of the tentacles and even of the pin- 

 nules there are spiculse; but they are here particularly small; they are all (see fig. 9) of 

 linear form, only somewhat tapering at the ends, and obtusely rounded (fig. 10), also every- 

 where rough with small irregular projecting nodules. 



In the youngest colonies of only 20 Mm. height (fig. 7) there was only one single 

 polyp developed; and this was situated at the point of the stem. In somewhat larger spe- 

 cimens there were indications of one or two other polyps below it. The budding of the polyps 

 seems thus to proceed from above downwards. The axis in these small specimens was par- 



