38 PENNATULIDA. 



allies is that the polyps are almost free and only few in each wing; further, the polyps in Dilbenia 

 are said to want calyces; generally, they are only contracted -- in very different degrees and not 

 with the circle of tentacles fully retracted; but that this circle may be completely retracted, is seen from 

 Kor. & Dan.'s fig. 3, I.e. PI. X 1 ), and it is also mentioned I.e. p. 95; when the circle of tentacles is re- 

 tracted the other part of the body of the polyp then forms a calyx; I find this feature to be quite 

 similar in Stylatula gracilis, in which, however, it is the rule that the individuals of the wing are 

 retracted. Finally, the lateral zooids are arranged in a group above each wing with numerous indi- 

 viduals, whilst in the other Stylatula-iorms they seem to be arranged in a single transverse row. 

 Altogether, these features seem to be too insignificant to justify a separation from Stylatula as an 

 independent genus; but, as my material of typical forms of Stylatula has been limited to one specimen 

 of St. gracilis, I think it better to leave the matter for future determination. 



Stylatula (Diibenia) elegans Dan. Kor. 



Virgularia elegans Dan. Videnskabsselsk. Forhdl. i Christiania 1859, S. 251. 

 Stylatula elegans Richiardi. Monografia etc., 1869, S. 73. 



K611. Monogr., 1872, S. 225, Tab. XVI, Fig. 13738. 

 Diibenia elegans Dan. Kor. Fauna litt. Norv. Ill, 1877, S. 97, T. Ill, Fig. i 7. 



abyssicola Ibid. S. 94, Tab. X og XII, Fig. i 3. 



borealis N. Nordh. Exp. Peun., 1884, S. 97, T. Ill, Fig. i 7. 



abyssicola Marshall. Rep. Triton Exp., 1883, T. XXIII, Fig. 1721. 



From the Vestman-Islands we have two fragments (17 and 2O mm , probably of the same colony) 

 of a zDubeniav with four polyps in the wings, above each of which is a group of zooids consisting 

 of several rows; the large needles of the < calcareous plate are 2.4 mra long, and at the thick end up 

 to 0.240""" broad; the smaller needles are 0.544 0.768" long, up to 0.048""" broad. The large needles 

 of the calcareous plate seem to grow in thickness at the proximal end in such a way that the original 

 long spicule is united with several of the smaller neighbouring spicules. The spicules along the aboral 

 side of the tentacle-stem are of a length of 0.064 o.i6o mm . The body of the polyps is without spicules, 

 or only provided with a few. The polyps measure up to 3'"'" (but the size is here, as is so often the 

 case, very varying according to the degree of extension). 



I have stated above that I cannot acknowledge the three established species as separate. 

 Neither from the descriptions, the figures, nor the specimens I have had the opportunity of examining, 

 can I discern any other difference than in the number of polyps in the wings and the number of 

 lateral zooids; and here where the number of polyps varies within the limits 2 6, this difference 

 means no more than in Virgularia, the mode of growth of the colony being the same as in that 

 genus (even Koren and Danielssen have given up laying absolute weight on the number of polyps 

 by making the form smaragdina a variety of abyssicola). Only in appearance are the specimens of 



') I find the feature to be the same in a great number of polyps in a specimen in our Museum ; it is determined as 

 D. abyssicola by Koren and Danielssen, aud has been sent from Bergen Museum. 



