ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 599 



it is also remarkably unstable. Precisely the same colouring matters are 

 present in the tentacles as in the rest of the animal, and as those in the 

 tentacles are due to yellow cells it is fair to conclude that those of the 

 latter have the same origin, and do not belong intrinsically to the animal. 

 The author cannot accept Krukenberg's view that the colouring matters of 

 Anthea are allied to " hepatochromates," because enterochlorophyll is not 

 nearly so easily decomposed as are the pigments of Anthea, and they are 

 at once distinguished by Stokes's fractional method. 



North Sea Alcyonida.* — Dr. D. Danielssen finds that the Alcyonids 

 collected by the Norwegian North Sea Expedition of 1876-8 are exclu- 

 sively deep-sea forms ; nine new genera belong to the Alcyonidae, in addition 

 to which there are two new species of Clavularia, one of Sympodium, one of 

 NidaJia, and a new genus and species representative of a new sub-family — 

 that of the Organinte. With regard to the anatomical and histological 

 details, the most important appear to be : — the discovery in Voeringia 

 mirahilis of a group of large ganglion cells on the uppermost part of the 

 ventral surface of the gullet ; these have a prolongation rich in protoplasm, 

 and under them there are smaller, round, pellucid cells and extremely 

 slender fibrils ; unfortunately, the condition of the specimens did not permit 

 of these interesting indications being more completely investigated. In all 

 the species examined the oesophagus had, on its inner ventral surface, a 

 groove coated with long flagelliform cells ; in Gersemiopsis arctica g. et sp. n., 

 the channel is divided longitudinally so that the gullet groove forms the true 

 oesophagus, and the remaining part may be regarded as an intestine. The 

 oesophagus is richly supplied with unicellular mucous glands, which were 

 also found in great abundance on the outer surface of the polyps of all the 

 species examined. It does not appear that there is no division of labour in the 

 colonies of Alcyonids, for in NepJithijs several species were found to have 

 special reproductive polyps ; and as soon as the elements are matured the 

 tentacles become curved in towards the oral aperture, which becomes closed 

 by a viscid mucous ; the gullet-tube becomes converted into a uterus, in 

 which development proceeds, and during this period such polyps are 

 nourished by others of the colony. 



Of the new genus Vceringia there are nine new species ; of Duva eight ; 

 of Drlfa two ; of Nannodendran one ; of FuUa one ; of Gersemiopsis one ; of 

 Barathohius one ; of SaraJiJca one, and of KrystaUofarces one. The new 

 sub-section Organinte has the zoanthodem poor in sarcosoma, the polyp- 

 cells are long and so arranged as to give to the whole structure somewhat 

 of the appearance of a collection of organ-pipes ; the new genus Organidus 

 has its single species dedicated to Baron von Nordenskjold. The plates 

 are as beautiful as in preceding memoirs of this series. 



Porifera. 



Systematic Position and Classification of Sponges.f — Dr. E. von 



Lendenfeld makes use of the nomenclature of the spicules recently estab- 

 lished by Messrs, Sollas, Eidley, and Dendy, but it is incomplete in so far 

 as the proposals of Prof. Sollas have been only partly published as yet. 



With regard to the systematic position of the Sponges, the view that 

 they ought not to be included among the Metazoa is rejected ; they are 

 Coelentera in the sense that the Coelentera and Coelomata make up the 

 Metazoa ; from what are ordinarily called Coelenterata (Nematophora or 



* Den Norske Nordhavs Expedition, 1876-8, xvii. Alcyonida. 4to, Cbristiania, 

 1887, V. and 169 pp., 23 pis., 1 map. 



t Proc. Zool. Soc. Lond., 1886 (1887) pp. 558-662. 



