PENNATULIDA. 



our specimen belongs to exactly the same species at that of Lindahl, and on the other hand also 

 very probable that it is a species different from U. encrinus. The young specimens of U. encrinus, 

 to be more particularly mentioned below, as well as the more or less young specimens with few 

 polyps in the cluster obtained by the Norwegian North-Atlantic Expedition, are far more robust and 

 short-stalked than this specimen or those of Lindahl; 1 think therefore that Danielssen's incorporation 

 of these latter into the species U. encrinus may, at least for the present, be regarded as unjustified, 

 the more so indeed as I cannot find the transference well-grounded by this author. 



During the cruise of the Michael Sars in 1902, a specimen of an Umbellula has been taken 

 which is very short-stalked when compared with the specimen just mentioned (PL III, figs. 40 — 45); it 

 thus has a robust appearance similar to the young U. encrinus; therefore, if the locality had not told 

 against it, I would have been inclined to refer this specimen to this species. The locality is St. 76 

 of the Michael Sars , 59 29' N. Lat, 7° 51' W. Long, south of the Wyville Thomson ridge, accordingly 

 within the warm area , the depth 580—689 fathoms. The tentacles, however, are much longer in 

 relation to the polyp-body, than is the case in the specimens of U. encrinus I have seen, being about 

 twice as long as the body. The length of the stalk is io7 mm , the length of its lower swollen part 

 23 mm , the diameter of the peduncle and the swollen lower part of the rhachis ca. 2 mm , the thinnest 

 part of the stalk ca. o.5 m,n , the length of its upper widened part ca. g mm , the length of the cluster 

 ca. 25 mm , that of the club of the rhachis ca. 6 mm , its breadth 3.5 mm . The cluster has five developed 

 polyps and one rudiment; the length of the polyp-bodies is 5 — 6 mm , that of the longest tentacles i3 mm . 

 The terminal polyp (P, figs. 40—41) is easily recognisable as such; on its right side are two fully 

 developed polyps and one small one, on its left side two developed polyps; the largest of the devel- 

 oped polyps is the one nearest to the primary polyp on the right, the smallest the second on the 

 left counting from the primary polyp. The small polyp is remarkable from the fact that its dorsal 

 arms are much smaller than the ventral (comp. below under U. encrinus). Above the circle of the 

 lateral polyps, ventral to the primary polyp, are two large zooids, each with a well-developed tentacle 

 with small side-branches; a similar large zooid is found to the left of the small polyp. Not only the 

 zooids of the rhachis-club, but also many of the zooids of the other parts of the stalk quite to the 

 lower swelling, show a tentacle ; on the small zooids of the stalk it is, however, very fine and delicate. 

 (This explains the want of a tentacle in the zooids of this region in the other specimens as probably 

 due to some accident.) 



This specimen has also the same numerous, small spicules in the lower end of the peduncle 

 (PI. Ill, figs. 44 and 45). In the living state the colour was reddish-brown passing somewhat 

 into violet. 



Being of opinion that the specimens of Lindahl and those described here, ought to be kept as 

 a separate species I have designated it with the name U. lindahlii given it by Kolliker in 1875 (1. c. 

 p. 10). The reason for referring the above described, quite small stage from the Davis Straits to this 

 species, is partly that the tentacles of the primary polyp are so long, partly and more especially the 

 locality where this specimen has been taken. When further, I have given U. gracilis Marshall and 

 U. bairdii Verr. as synonyms, I have done so as a matter of judgement, as the description of these shows 



