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X. Oti the Genus Lcmnalia, Gray ; icith an Account of the Brunchiny-systems of the 

 Order Alcyonacea. By Gilbert C. Bourne, M.A., F.L.S., Fellow and 'Tutor of 

 New College, Oxford ; University Lecturer in Comparative Anatomy . 



(Plates 40-42.) 



Read 16tli Febniarv, 1899. 



In the course of a description of the Anatomy of Alcyonium digitaium, Hickson * lias 

 called attention to the unsatisfactory and misleading terms employed in the descrip- 

 tion of Alcyonarian polyps and colonies. It is the fact that, ^^ liile Allman and Haeckel 

 have provided us with a set of precise terms descriptive of the component parts of the 

 Hydrozoa, the terminology of the Anthozoa remains in a state of the utmost confusion. 

 For cxam2ilo, the name " polyp " is applied sometimes to the whole Alcyonarian zooid or 

 individual, sometimes only to that j^in't of it, whether retractile or non-retractile, which 

 emerges from the surface of a colony. The name " coenenchyme " is applied to any mass 

 of tissue in which the zooids are imbedded, no distinction being made between the 

 various modes in which zooids may be aggregated together to form a mass or colony. 

 The name " stolon " is used to denote the root-like basal outgrowths by which the 

 Cornulariidce are attached to foreign objects, and also the canals lined by endoderm 

 which place the cavities of the zooids composing a colony in communication, and form 

 so large a part of the so-called coenenchyme of colonial Alcyonarians. It is unnecessary 

 to give further examples ; these few will suffice as a justification for my burdening 

 zoological literatvire with a new set of descriptive terms. I do not, however, propose to 

 suggest a complete set of terms for the whole of the Alcyonaria in this paper, but to 

 confine myself to the Oi'der Alcyonacea. Some of the terms projiosed are applicable only 

 to the members of this order, others are applicable to all Alcyonarian zooids. In the 

 first place I wish to substitute the name " cwo«rf " for that of " j}oli/p" f. The name 

 zooid is applicable to any asexually-produced individual entering into the composition 

 of a colony, and therefore Kolliker was in ei-ror when he restricted it to those 

 arrested and modified individuals whose function it is to drive currents of water through 

 Alcyonarian colonies. These should be called siphonozooids. Tliereare, of course, many 

 kinds of zooids, since there are many groups in the animal kingdom in which asexually- 

 produced individuals are united to form colonies, and these may be distinguished as 



* S. J. Hickson, "The Anatomy of Alcymiium diijitdium,''' Quart. .Journ. Mier. Sci., new ser., vol. xxxviii. 

 p. 354. 



t See Moseley, 'Challenger' Reports, Zoology, vol. ii. p. 118, and Milnes-Marshall, Trans. Roy. Soc. Ediuburgh, 

 xxxiii. 1888, p. 453. 



SECOND SERIES. — ZOOLOGY, ""^OL. VII. 72 



