NOTES AND MEMORANDA. 279 



of organs of nutrition, is that the ectoderm fulfils the function of the 

 entoderm, and the animal nourishes itself by its ectoderm absorbing the 

 organic material dissolved in sea water, a supposition the more pro- 

 bable as he has already demonstrated the same fact in sponges.* 



Muscle-epithelium in Anthozoa — Dr. 0. Kling publishes a pre- 

 liminary communication on this subject, f in which he studies the 

 exact relation of the so-called neuro-muscle cells in the genera Adi- 

 nozoa, namely Actinia (^equina') and Muricia. In both these genera he 

 finds that the muscular layer occurs on the inner (endodermal) side 

 of the supporting lamella, and that the cells of which it is composed 

 are in evident connection with the endodermal cells. 



The arrangement in these forms is therefore the exact opposite to 

 those which obtain in Hydra, in which, as Kleinenberg showed, the 

 neuro-muscular cells are undoubtedly ectodermal. This seems to 

 show that the mesoderm, like the generative products, may have 

 originally sprung indilferently from either layer. 



Phylogeny of the Antipatharia. — This subject is discussed in a 

 paper | by G. v. Koch, who begins with a description oi Antipathes larix 

 and Gephyra Dohrnii, and afterwards discusses the probable steps in 

 the evolution of the Antipatharia, which he considers to have been 

 as follows : — 



1. Soft-bodied Actinice secreted a horny substance from the ecto- 

 derm of the disk of attachment. 



2. Those of the foregoing forms, which were attached to thin 

 cylindrical supports, surrounded the latter and covered them with a 

 horny substance, which, in the case of polypes occurring in large 

 groups, served to unite them by their bases. 



3. These polypes, living singly or in groups, became united, by 

 means of stolons, into a colony. The axial skeleton no longer existed 

 exclusively as an investment to some support, but gave off independent 

 branches. 



4. The separate parts of the polypes underwent retrogression. 



5. The colonies (zoanthodemes) assumed a greater independence 

 of form, while the axial skeleton no longer retained the form of an 

 investment of a foreign support. The polypes decreased in size 

 concomitantly with the increase of their numbers on one colony ; 

 with this diminution in size was connected arrest of the mesenteries 

 and tentacles. 



Skeleton of the Alcyonaria. — A study of this interesting group 

 of Actinozoa has been made by v. Koch.§ In the first part of the paper 

 the author gives a description of the anatomical character of the 

 following genera and species : — Sderogonia Mexicana,Mopsea erythrcea, 

 Melithcea, Muricea placomus, Isis elongata, Primnoa verticillans, Penna- 

 tula rubra, Haliscepfrum Gustavianum, and Kophobelemnon Leuckartii. 



The second part is occupied with a description of the skeleton of 



♦ 'Ann. and Mag. of Nat. Hist.,' iii. (1879) 177. 



t ' Morphol. Jahrb.,' iv. (1878) 327. 



X Ibid., iv. (1878) 74. § Ibid., iv. (1878) 447. 



