HYDROIDA II ™- 



call}' ill the Norwegian Sea, and lie also comparativeh' near the submarine ridges. It was therefore 

 most likeh- that the species should be reckoned, bio-geographically, as belonging to the class of sucli 

 visitors, and the two new finds appear to confirm this supposition, Ijotli being situate in the wanner 

 atlantic region; one on the slope down towards the Atlantic Deep, west of the Faroe plateau, and the 

 other on the east side of the threshold in Danmark Strait, where several other warm-water sjjecies 

 also come in. The last-named locality, with a depth of 138 fathoms, is the shallowest of the finds 

 made; the others lie deeper down in the true abyssal region. We are therefore justified in concluding 

 that the species belongs to the warmer and deeper atlantic communities. 



Aglaophenopsis iFewkes). 



Upright colonies with branched or unbranched main stem, the apophyses bearing unbranched 

 hydrocladia with several hydrothecfe. All the sarcothecae are immobile. The gonothecse are protected 

 by minor branches forming a basal appendix to the h^'drocladia, and with both hydrothecae and sar- 

 cothecae; the gonothecse are situate on the stem or on the minor branches. 



Practically speaking, this definition coincides with Nutting's limitation of the genus (1900 

 p. 118). Nutting also lays most stress upon the occurrence of the protective branchlets, but does 

 not seem quite to have realised that the principal character for these lies in the fact that they bear 

 h\drothec;e, not, as in the case of Cladocarpiis^ sarcothecae oiilv. Aglaophenopsis differs from \nnato- 

 ciirpiis in principle by the fact that the minor branches do not develope into secondary hydrocladia of 

 normal appearance, but merely appear as protectix'e appendices in fertile colonies. 



Aglaoplioiopsis-Cladocarpus form a pair of genera parallel with Thrcocarp7is-Aglaoplic7iia. As 

 a matter of fact, we cannot determine which of the two in each case is the more primitive; having 

 regard, however, to the development of a species such as Ncinatocarp-iis ramulijicrus^ which appears to 

 be more primitive than the others in the state of its gonangia, we must probably incline to the theory 

 that Cladonupits and Aglaopluiiia are the more primitive, rather than the more highly de\'eloped. 

 Still, we can hardly in either case regard the one genus as derived from the other; it would seem 

 more likely that each has arisen independently. 



Aglaophenopsis COrnuta (Verrill) Nutting. 

 1879 CladocarpHS contrifus, Verrill, Notice on recent additions to the marine fauna, p. 310. 

 1900 Aglaoplioiopsis coniut<t. Nutting, Plumularidce, p. 120, pi. 30, figs. 6—9. 



Colonies doubly pinnate, with branched polysiphonic main stem, monosiphonic in its extreme 

 portions. The priinar\- stem tube is divided into short internodia, bearing in the middle an apophyse 

 directed obliqueh- forward and sideways, and three sarcothecte, one pair nearest the upper side of the 

 apophyse, and an unpaired one mediallv on the lower part of the internodium; all are split along the 

 upper side, and project far forward, especially the paired ones. At the base of the apophyse, between 

 it and the unpaired sarcotheca, there appears a pattern which must be interpreted as an abortive 

 hydrotheca. The hydrocladia have on the rear side a markedly prominent keel: they are divided into 

 short internodia, each bearing a large hvdrotheca and three sarcothecae, a supracalycine pair at the 



