PENNATULIDA. 41 



triangular form being composed of three ridges. As to the colour, it can now (i. e. for spirit specimens) 

 only be said that the part of the polyps projecting outside the calyx, as also the stomach, is chocolate- 

 coloured, or deep reddish-brown. 



These four specimens show so much correspondence with the Microptilum of Kolliker, estab- 

 lished on a specimen of the species M. mllemoesii from Japanese seas (Rep. Chall. Penn. p. 26, PI. VII, 

 fig. 27) that they may undoubtedly be referred to this genus. This I have done originally; but on 

 a visit to the Bergen Museum in 1897 I had the opportunity of examining the type-specimens in that 

 collection of Lygomorpha Sarsii Kor. & Dan., and I very soon recognized this genus and species to be 

 young stages of Halipteris christii; now these Ingolf-Microptiles show no slight resemblance to 

 tLygomorphav, as will also be seen from figs. 29 and 31 on PI. II. The arrangement of the polyps is 

 the same in both, as also the structure of the calyx etc. I therefore referred them to Halipteris, being 

 of opinion that both Microptilum K611. and Lygomorpha Kor. and Dan. were to be referred to Halipteris 

 as young stages of this genus. Later, when I had the opportunity of studying the genus Pavonaria 

 more thoroughly, I came more and more to the conviction that the Ingolf-Microptiles would have to 

 be referred to Pavonaria ; I wished therefore to test their resemblance to Lygomorpha by a direct com- 

 parison of the specimens. The Bergen Museum, with the greatest friendliness, met my wish and sent 

 me the type-specimens of Lygomorpha. With regard to Lygomorpha the result was the same; it is 

 decidedly a Halipteris, but it is as decidedly different from the Microptiles of the Ingolf. To men- 

 tion only a single case: the long calyx-spicnles of the latter are on an average twice the length of 

 those in Lygomorpha, whilst the spicules of this latter agree with those in Halipteris. 



That I am right in referring these Ingolf-Pennatulids to the Microptilum of Kolliker will, I 

 think, be evident, when one compares Kolliker's figure of M. mllemoesii with the fragment of the Ingolf- 

 specimen Nr. 2 shown in fig. 36, and also the descriptions. The most essential difference is that the 

 genus Microptilum is said to have only one ventral calyx-point This one point, however, is 

 really two points fused together. At the British Museum I had the opportunity of examining the 

 type-specimen of M. mllemoesii, and thereby to verify, not only the resemblance to especially the 

 smallest of the Ingolf-specimens (Nr. 4) already seen in the figure of Kolliker, but also just the 

 feature mentioned of the double nature of the calyx points. The Challenger-specimen, however, which 

 is only 65'"'" long, has a terminal polyp in which the calcareous axis ends; this polyp seems to be 

 provided with eight calyx-teeth, but in the others the calyx-teeth are arranged into two ventro-lateral 

 points with an indentation between them on the side turned towards the stem, where the circle 

 of tentacles of the polyps etc. may be seen; in most, the two teeth are joined close together ventrally 

 but the arrangement of the spicules distinctly shows the double nature. Except in the four upper- 

 most polyps a small, younger polyp is placed at each of the others, immediately above the larger 

 one. The form of the calyx, the arrangement of the polyps etc. leave no doubt that Micr. mllemoesii 

 and our Ingolf-specimens belong to one genus; but it is beforehand little probable that they should 

 belong to one species; I shall, however, return to this question later. 



Verrill has already said that the genus Microptilum of Kolliker is a young stage of Pavonaria; 

 he has set forth the opinion (Am. Journ. Sc. (3) Vol. 23, p. 311) that most, if not all, the members of the 

 families Protocaulidce and Protoptilid(E of Kolliker are young stages of other Pennatulids; and though 



The Ingolf-Expedition. V. i. 6 



