516 DR. HUBRECHT ON A NEW PENNATULID. [May 19, 



they were in spirit. This would also explain how it was that 

 internally all traces of cell-structure had vanished, that no staining 

 methods were of any use, &c. Careful preparations of parts of the 

 rhachis-wall spread out and looked at from the inside, showed that 

 the polyparia indeed contained polyps (and that the zooids did not), 

 moreover showed remnants of the mesenterial filaments, but how the 

 internal soft parts were respectively related could not possibly be 

 made out. I must leave this to a more fortunate student of 

 specimens in the fresh state. 



There only remains for us to inquire whether the structure of the 

 polyparium, as we have described and partly figured it, will enable us 

 to decide about the degree of relationship which the new genus, pro- 

 posed to be called Echinoptilum, has to the other genera and groups 

 of Pennatulids. 



It is undoubtedly amongst the less specialized famiUes of Seapens 

 that we must look for its nearest allies ; and were it not for the 

 incipient differentiation of a dorsal and ventral surface, and more 

 especially for what sections teach us in this respect, we should feel 

 inclined to arrange Echinoptilum in the very lowest section — the 

 Veretillese, which, by the radial arrangement of the polyps round 

 the rhachis, still more closely approach the Alcyonaria s. str. {Alcyo- 

 nidcB &c.). For the reasons just recalled to mind we have, however, 

 to arrange the new genus in Kolliker's other large section, that of 

 the Spicatse, which is characterized by a bilateral arrangement of the 

 polyps on the rhachis. In this section the less differentiated families 

 of the Kophobelemnonidae and the Protoptilidfe have several struc- 

 tural peculiarities in common with Echinoptilum ; and the new genus 

 of Protoptilidse, Gunneria, only very lately described by Danielssen 

 and KorenS more especially resembles Echinoptilum in its very 

 massive development of needle-like calcareous elements in the 

 sarcosoma. Moreover the external appearance of the individual 

 polyp-cells in Echinoptilum and the arrangement of the spicules in 

 the wall of these is met with in other Protoptilidse. 



The general aspect of Echinoptilum, its shortness and club-shape, 

 more especially resembles that of Kophobelemnon, the ProtoptilidaR 

 being long and slender, and their polyparia reminding one of the 

 unbranched Gorgonidse. The calcareous needles also are very 

 profusely represented in the investment of the Kophobelemnonidae, 

 but are not found in the internal delicate framework of this family, 

 whereas, on the contrary, in Echinoptilum we find it thickly beset with 

 them. Again, the individual polyp-cells of the ProtojitiUdse have 

 more resemblance to Echinoptilum than those of Kophobelemnon, 

 ■where they are much less marked and projecting. 



On the other hand, we must not lose sight of the fact that with 

 another section of the Spicatse, viz. the Funiculinese, Echinoptilum 

 has also more than one point of comparison, more especially with 

 Kolhker's new genus Stachyptilum {' C\\?A\e\\^ev' Reports, vol. i. 

 Pennatulids, p. 12, pi. viii. figs. 24-26). The polyp-cells in Echi- 



^ Der Norske Nordhavs Expedition, xii. Zoology, Pennatulida : Ohristiania, 

 1884. 



