SALICORNARIIDiE. 21 



nodes, whilst in the former the branches are continuous, as in a branching Eschara or 

 Cellepore. The junction between the separate joints or internodes in all recent 

 Salicornariidac is effected by means of flexible, chitinous tubes, and it is extremely rare to 

 meet with an instance of rigid anchylosis between them. In one recent species, however, 

 {Sal. malvinemis, nob.), the two internodes may occasionally be seen thus united, whilst 

 the rest of the growth retains the flexible condition. This observation is of particular 

 interest with regard to the fossil Salicornarise of the Crag, in which a rigid connexion 

 appears to be far more frequent, although, notwithstanding this frequency, little doubt 

 can be entertained that it is what may be termed accidental or exceptional, as in Sal. 

 malvinensis. It will be observed that even where anchylosis has taken place, the 

 apparent branch is contracted at the point of junction, which is not the case in the true 

 Vincularice, of which one well-marked recent species at any rate exists. It follows from 

 this, therefore, that fragments of a fossil Salicornaria may, in most cases, be distinguished, 

 among other characters, by their tapering towards the ends. The peculiar angular areo- 

 lation of the surface, and the presence of scattered immersed avicularia, are other characters 

 also sufficiently diagnostic of the genus, which we consequently fully agree with 

 Dr. Hagenow in regarding as altogether distinct from Vincularia, Defrance, a term which 

 should be restricted to the continuous, cylindrical polyzoaria which seem to have pre- 

 dominated in past periods, whilst the true Salicornarice appear to have been gradually 

 increasing in number of species up to the recent epoch. 



With respect to the appropriate appellation of the genus, the synonymy above given 

 will show that great confusion has existed. 



The Salicornariida, or species having articulated polyzoaries composed of cylindrical 

 internodes, in which the cells are disposed around an imaginary axis, were originally 

 confounded by Pallas under his genus Cellularia, and by Solander under that of Cellaria, 

 with many others not possessing that peculiar characteristic. The term Cellaria, it is true, 

 was afterwards restricted by Lamouroux to those species which had cylindrical branches, 

 or rather in which the cells were disposed around a central axis ; but as this definition 

 would also include Vincularia and our genus OncJtopora {' Quart. Journ. Mic. Soc.,' iii, 

 p. 320, 1855), it would not be equivalent to /S'fl/ecorra^na, as here understood. And as it 

 might also be readily confounded with the more extensive Cellaria of Dr. Solander and 

 most authors except Blainville, it seems hardly advisable that it should be readopted in 

 again an altered sense. Among the other appellations already in use, none appears 

 more suitable or less liable to be misunderstood than that of Salicornaria Cuv., which 

 has moreover the advantage of having already been very generally adopted. 



It is necessary to explain a few of the terms employed in the description of the 

 Salicornariid^e, which appear to be demanded by some peculiarities belonging to them. 



1. The angular spaces into which the surface of the internodes is divided, and each 

 of which corresponds to the outline of a cell, are termed the area. 



2. The orifice perceptible in many of the cells at the summit of the " area," and. 



