54 



PENNATULIDA. 



quite special; as to the red colour, great stress is hardly to be put on it, as it probably is very widely 

 varying in intensity, for example in Pennatula phosphorea where the red colour may quite disappear 

 (comp. also Protoptilnm thomsoni) ; and the unnamed Challenger-specimen Nr. 2 is of the same intense 

 red colour as our specimens. 



If I have, nevertheless, designated these specimens not as P. aberrans but as P. carpenteri, I 

 have done so because I think these two species to be synonymous, and the name carpenteri is 

 the older one. To be sure Kolliker says of Pr. carpenteri that the polyps are placed in two rows 

 on either side of the pen; but it is very difficult to get a clear view of these double rows as 

 the ventral median line is not distinctly marked, and at all events they are not found through- 

 out the whole length of the rhachis. The figures given by Kolliker (Mouogr. PI. XXIV, 223, 224) 

 show an arrangement, essentially agreeing with that of some of the specimens of the Ingolf (comp. 

 the figured fragment, in which a two-rowed arrangement is quite distinctly beginning); and of 

 Pr. aberrans Kolliker himself says that in some places the polyps show a tendency towards the ar- 

 rangement seen in P. carpenteri. The whole difference in the arrangement of the polyps is certainly 

 only a difference in individual development, and cannot consequently be made the base of a separation 

 into different species of the forms aberrans and carpenteri, which agree so exactly in all other features. 

 But if it is a fact that the one-rowed arrangement of the polyps may here pass into a two-rowed 

 one, the question arises, if Prof, carpenteri-aberrans is not upon the whole only a young stage of a 

 Protoptilum with more longitudinal series of polyps and a correspondingly larger number of zooids. 

 This, perhaps, will turn out to be the case, and I think I may point out Pr. thomsoni as the further 

 developed form in question; there is really in the calyx-form, the polyps and zooids, the spicules etc. 

 of this species a tolerably close agreement with those of Pr, carpenteri, and all the differences are 

 more particularly such as might be due to differences in age and growth. As there is, however, a 

 recognizable difference in outward appearance from the least developed stages of the forms I refer to 

 Pr. thomsoni -- the whole colony of the latter is especially much more robust -- I have thought it 

 best for the present to keep the species Pr. carpenteri. 



Occurrence. Pr. carpenteri has been found before in the Atlantic by the Porcupine* Ex- 

 pedition, at 48 31' N. Lat, 10 03' W. Long., 690 fathoms (the type-specimen of Kolliker); 48 50' N. Lat, 

 11 9' W. Long., 725 fathoms, 2 specimens (Marsh. & Fowl.); by the Challenger Expedition (Pr. aberrans) 

 south of New York, 37 25' N. Lat, 71 40' W. Long., 1700 fathoms; 31 34' N. Lat, 72 10' W. Long., 1240 

 fathoms; 40 17' N. Lat, 66 48' W. Long., 1350 fathoms. In addition, V err ill (Am. J. Sc. (3) vol. 23, p. 312, 

 note) states that he has found the same species (as aberrans) in shallower waters, and adds that in 

 some of the larger specimens the polyps are arranged in groups of two or three individuals. (When 

 Verrill on this account thinks the genus Protoptilum to be evidently the young of Virgularia^ he is 

 quite wrong, which need not be shown more particularly ')). 



By the discoveries of the Ingolf and the Thor, the territory of the species has accordingly 

 been considerably extended towards the north; probably it comprises the whole northern part of the 

 Atlantic inside the warm area, where the depth, bottom, etc. are suitable. 



') Grieg has already and justly objected to this view (Norges Pennatulider pp. 15 16). 



