8d 
THE VOYAGE OF H.M.S. CHALLENGER. 
circular, or elliptical. Ocecia inconspicuous, opening at or near the summit of the area 
above the orifice. In the decalcified condition the interareolar septa exhibit a delicate 
chitinous probably tubular filament apparently continuous throughout the segment; and 
on each side of the oral orifice a slender curved chitinous rod or trabecula, which some- 
times unite so as to form a complete or incomplete ring. Avicularia usually present, 
either vicarious or intercalated. 
The Family Salicornariadse, as thus constituted, appears to be a very natural one. It 
includes besides Salicornaria or Cellaria, the genus Melicerita of M. Milne-Ed wards, 
the close relationship of which to Salicornaria has also been perceived by Mr. Waters. 1 
Under the name Salicornaria I have included all the cylindrical forms, though 
strongly inclined to separate Salicornaria magnifica from the rest, on account of its 
unjointed branched zoarium, and the absence, so far as I have been able to perceive, of 
any avicularian organs. 
As in very many other cases, the chitinous elements of the skeleton will in this Family 
be found of the utmost value in diagnosis, as affording the most distinct and invariable 
characters. Among these elements are included, besides the opercula and avicularian 
mandibles : — 1. A delicate, sometimes distinctly tubular filament, running along the 
interareolar septa, and affording probably a channel through which the extension and 
calcification of the septa are effected. This filamentary network appears to be continuous 
throughout the branch or internode, and the network formed by it should be regarded 
as zoarial rather than as appertaining to the individual zooecia enclosed in the meshes. 
2. A second chitinous element, peculiar, so far as I am aware, to this Family, consists 
in the delicate rods or trabeculae on either side of, or completely surrounding the orifice 
and its operculum, to which the rods or ring afford support. It may be added that 
these trabeculae or the analogous chitinous ring are plainly visible, in many cases without 
any previous decalcification. This is especially seen in Salicornaria magnifica and 
Melicerita atlantica. They appear to lie beneath the common epitheca and not to form 
mere thickenings of it. 
A further peculiarity, common, so far as I know, to the whole Family, is the existence 
of a rounded apparent opening at each lower angle of the operculum, and which in the 
descriptions of several species are termed “ foramina.” Subsequent examination, however, 
seems to show that these marks are not really openings, but in all probability merely the 
optical expression of the bases of short conical projections on the dorsal surface of the 
operculum — a sort of levers — for the attachment of the occlusor muscles. 
1 Quart. Journ. Geol. Soc., August, 1881, p. 332. 
