PENNATULIDA. 



27 



Together with some of the more developed stages the\- have been obtained by Loxeii in i<S32, partly 

 at Kulleii (MoUe), partly at Bohuslan. 



The youngest stages measure 10, iO"5, and ii-5""". One s])ecimen io-5'"'" long, is figured on 

 PI. II, fig. 2S, seen from the dorsal side. The upper, polyp-bearing part of the rhachis measures ca. 4"""', 

 the part with the zooids 3'5'""\ so that the length of the peduncle proper is 3""". On cither 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 polvp 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""" 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 abrupth', as if cut off, in the thin sarcosoma; accordingh', its 

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

 stem is not occupied hv a developed pol)p which might be regarded as the terminal polyp, but there 

 are at the top two somewhat alternating and quite rudimentary polyp.s, 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 highh' 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 atrophv, 

 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 n-^'™ long") is provided with 66 solitary polyps, 

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

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

 appearance, and is ver\- little similar to the young imperfect pohp-buds at the lower end of the shaft. 



A number (8—9) of small colonies, 11 — 22""" long, appear somewhat more developed, in that 

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

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

 the rhachis consists of oul\- one polyp (on the left side there are 4 such, on the right side onh' 2), 

 each of the following wings lower down have two pohps, 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 rudimentar\- wings two lateral zooids are found, under the upper solitar>- 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') 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 rliachis; on account of the transparent sarcosoma the lower one 

 may distinctly be recognized as a D/stoma. 



2) These are not .tfiven in the fij^ure. as thex- are only seen under rather hiijh ma,<jnifyiug powers. 



4* 



