8o 



PENNATUUDA. 



polyp-bearing rhachis-club. The whole stalk is covered with zooids, downward to the upper part of 

 the lower swelling, where the cessation of the zooids shows the boundary to the peduncle. Of the 

 zooids of the stalk, those of the upper swelling are almost always provided with a tentacle like those 

 of the rhachis-club; but also farther down the stalk, for instance in the thinnest part of it, the zooids 

 may be provided with a tentacle, but it is then a very thin one; most likely all zooids have this 

 equipment, but the thin tentacles are easily torn off, and this I take to be the reason why it seems 

 to be wanting in most of the zooids of the stalk. The upper part of the stalk, below the rhachis-club, 

 is twisted and bent in various ways, but always in such a manner that the cluster remains pendent; 

 further the whole stalk, above the lower swelling, is turned like a spiral round its longitudinal axis. 

 The calcareous axis is quadrangular with deeply concave surfaces and rounded edges. Very small 

 spicules are found, but only in the lower end of the peduncle. The colony grows to a 

 height of more than two metres. 



Of this species the <Ingolf > brought home five specimens (the Nrs. 2, 3, 5, 6, and 7 of the table 

 below), and later the Amdrup — Hartz Expedition has brought three more specimens (Nrs. 1, 4, and 8), 

 Caud. Jensen from the cruise of the «Mich. Sars>, two specimens (Nrs. 9 and n), and the steamer .Thor , 

 one (Nr. 10). The particulars with regard to these specimens are given in the table below, which shows 

 that only six specimens have kept the stalk entire, or kept it so far, that it has been possible to 

 measure its length (Nrs. 4 and 10 are broken and parts of the calcareous axis wanting), and that two 

 of these six are young stages; the specimens Nrs. 8 and 11 are torn off clusters and in a very bad 

 condition, and therefore some of the measurements given are rather uncertain. I think that the spec- 

 imen Nr. 3 is the longest one hitherto measured. 



Nr. 

 Locality 



Cape 

 Brewster 



St. 105 ; St. 116 



4- 



Canning 

 Land 



St. 116 



St. 1 16 St. 116 



Canning 

 Land 



9- 

 M. Sars 

 St. 34 a 



< Thor> 

 St. 51 



11. 



«M. Sars 

 St. 34 



Length of the stalk . in nun. 



Length of the bulbous part 

 in 111111. 



Diameter of the lower end of 



the peduncle in mm. 



Diameter of the swelling above 



the peduncle in mm. 



Diameter of the thinnest part 



of the stalk in mm. 



Length of the sheath-formed 



dilation in mm. 



Length of the cluster . in mm. 



Length of the rhachis-club 



in mm. 



Breadth of the rhachis-club 



in mm. 



Number of polyps 



in the lower 



circle 



148 



215 

 40 



2 2.5 



2 3 



0.5 0.5 



10 9 



17 23 



2-5—3 3-5 



4(+i) 7(+4) 



2350 

 312 



17 

 23 



1090 



24 

 5-6 



c. 100 



170 



40 

 40 



no 125 



38 43 



1090 

 230 



17 

 iS 



4.5 

 c.6o(?) c. 84 



105 c. 85 



150 

 33 



35 



4o 39(37 + 2)] 38 3S1) 29 37(31+6) 



128 



c. 40 



37 

 25 



3(+i) 



6(+4) 



1410 

 290 



17 

 c. 25 



c-5 



c. 100 

 c. 130 



40 



42 

 41 



c. 90 — 92 



30 



21 

 25 



T ) Several small polyps, but none still in the rudimentary stage. 



