PENNATULIDA. 45 



Halipteris christii (Kor. & Dan.). 



PI. II, Figs. 30, 31, 32. 



Virgularia Christii Kor. Dan. Nyt Mag. for Naturvidensk. 5 Bd. 1848, S. 269; Faun. litt. Norv. II. 1856, 



S. 91, Tab. XII, Fig. 712. 



Norticina Christii Gray. Catal. Sea-Pens, 1870, S. 13. 

 Halipteris Kolliker. Monogr., S. 241, Fig. 146, 147. 



Lygomorpha Sarsii Kor. Dan. Faun. litt. Norv. Ill, 1877, 8.99, Tab. IX, Fig. 7 12. 



Protoptilum tortum Grieg. Bergens Mus. Aarbog 1886, S. 13, Tab. VII, Fig. 19, 20, Tab. VIII, Fig. 13. 

 Stichoptihim arcticum Grieg. Ibid. S. 15, Tab. VIII, Fig. 4, 5, Tab. IX. 



From a fishing bank ca. 20 miles east of Fuglo, the Fseroe Isles, the Copenhagen Museum 

 received through Agent Miiller in 1899 a fine and complete specimen, 1040""" long, of which the 

 peduncle makes only 8o nim , and again in 1902 from the same donor an excellent, smaller specimen 

 from the Fseroe Isles, 400""" long (the peduncle 56 mm ). 



Young stages of this species differ so much from the grown form, that they have been 

 described as independent genera and referred to quite a different family. On some of them Kor en 

 and Danielssen have formed the genus Lygomorpha^ on others Grieg has formed the genus Sticho- 

 ptilum, whilst some specimens have been referred by the same author as a new species to the genus 

 Protoptilum K611.; all these <.genera were again gathered into the family Protoptilida of Kolliker. 

 That I can now with perfect surety refer them to their right place as Halipteris christii, is due to 

 the circumstance that I have been able to examine the respective type-specimens, and to compare them 

 with one another, and with a large and good material of larger and full-grown specimens; upon the 

 whole I have had before me a tolerably entire series from a length of ca. 73 mm up to about four feet. 



The most important aid to recognizing the younger stage as Halipteris christii is the form of 

 the calyx. The arrangement of the polyps will naturally vary; in the youngest specimens one 

 must expect a more or less distinct arrangement in two rows, in the somewhat older ones we must 

 expect to find new polyps on the inner side of the original rows (i. e. somewhat nearer to the ventral 

 median line). 



In large specimens of Halipteris christii the polyp-calyx has a somewhat different appearance, 

 according as the polyps are stretched out or more or less retracted, and to this is to be added that 

 the two abaxial calyx-points may vary somewhat in size; generally they are short, one (the inner 

 one) is often quite indistinct, which may also hold good with regard to the outer one; this 

 however, will scarcely ever be found in all the polyps of one and the same specimen. When the 

 polyps are much expanded the mouth of the calyx is distended, and then the two teeth may be widely 

 separated and are easily overlooked; when, on the other hand, the polyps are quite retracted, the 

 mouth of the calyx is drawn together; then the calyx is very similar to a grain of wheat, and in 

 well-preserved specimens the calyx-points are always seen distinctly. They are supported by layers 

 of spicules continuing down the calyx. The longest of these spicules I have found to be of fairly 

 constant length - - having measured them in several specimens, both large and small; on an average 

 they are some o.48o mm long, o.o32 mm broad; the very longest I have found to be 0.496'""' long, o.o4o mm 



