PENNATULIDA. 



Together with some of the more developed stages they have been obtained by Loven in 1832, partly 

 at Kullen (Molle), partly at Bohuslan. 



The youngest stages measure 10, 10-5, and ir$ mm . One specimen io'5 mm long, is figured on 

 PI. II, fig. 25, seen from the dorsal side. The upper, polyp-bearing part of the rhachis measures ca. 4""", 

 the part with the zooids 3'5' nm , so that the length of the peduncle proper is 3""". On either side of 

 the rhachis there is a row of five distinct polyps decreasing in size and stage of development from 

 above; the polyps of one side alternate with those of the opposite side; only in the row on the right is 

 there at the lowermost polyp but one, on the ventral side of the colony, a small rudiment of a wing- 

 polyp No. 2. Below each polyp one lateral zooid is found. In addition, the lower part of the shaft, 

 which is devoid of polyps, carries on either side a longitudinal row of four distinct and large stalk- 

 zooids. The uppermost is placed about i mm below the lowermost polyp-bud, and the zooids of the 

 two sides are somewhat alternating in position. At the first glance, the upper end of the stem seems 

 quite intact, and no naked part of the calcareous axis projects; but on a more thorough examination 

 the calcareous axis is seen to end quite abruptly, as if cut off, in the thin sarcosoma; accordingly, its 

 upper end does not taper to the fine thread, usually found in Pennatulids. Further, the top of the 

 stem is not occupied by a developed polyp which might be regarded as the terminal polyp, but there 

 are at the top two somewhat alternating and quite rudimentary polyps, without tentacles; below 

 each of them is a lateral zooid, so that they prove to be wing-polyps. Thus the features at the top 

 are already highly changed; at all events, the terminal polyp and the upper end of the calcareous 

 axis have disappeared, and the two wing-polyps that are now the uppermost ones are about to atrophy, 

 or - - what I think less probable - - to regenerate. The specimen is excellently preserved, so that the 

 radiate canals in the rhachis are easily recognised, and there are no traces of generative organs. 

 The two other specimens agree in essential features with the one described, the only difference being 

 that all the wing-polyps are solitary. The specimen 11-5"" long 1 ) is provided with 6/6 solitary polyps, 

 each with a lateral zooid below, and four stalk-zooids. At the upper end of the axis a rudimentary 

 polyp is found only on the left side; but this polyp has to an important degree a distinctly atrophied 

 appearance, and is very little similar to the young imperfect polyp-buds at the lower end of the shaft. 



A number (8 9) of small colonies, n 22 mm long, appear somewhat more developed, in that 

 some of the wings are provided with two polyps. A specimen is figured on PI. II, fig. 26, seen from 

 the ventral side; it is 22 mm long, with a peduncle of 4'5 mm . Each of the wings of the upper part of 

 the rhachis consists of only one polyp (on the left side there are 4 such, on the right side only 2), 

 each of the following wings lower down have two polyps, likewise the distinct rudimentary wings 

 under these show two polyp-buds with perceptible difference in age. Under each of the wings with 

 two polyps and rudimentary wings two lateral zooids are found, under the upper solitary polyps only 

 one such zooid. The number of stalk-zooids is doubled (8 on the right side, 9 on the left), and the 

 lowermost indistinct rudimentary wings 2 ) almost reach the uppermost of them. To judge by the 

 size, each of the new stalk-zooids seems to have arisen in the interspace between two of the older 



') In this specimen two parasites are present in the rhachis; on account of the transparent sarcosoma the lower one 

 may distinctly be recognized as a Distoma. 



2 ) These are not given in the figure, as they are only seen under rather high magnifying powers. 



4* 



