364 Rev. T. Hincks’s Contributions towards a 
a colony of Pedicellinopsis in health and vigour must present a 
strange scene of unrest and lively movement. We may hope 
that Mr. Wilson may yet have an opportunity of examining 
the species alive and studying its habits. 
This localization of the muscular power seems to me to be 
fairly accounted a generic character ; and I should be disposed 
to separate Pedicellina gracilis from the species in which it 
is diffused and in which there are no chitinous elements. At 
the same time it must be remembered that Leidy has described 
an American form very closely resembling P. gracilis, in 
which the basal expansion is present, while at the same time 
the whole stem is highly flexible and often becomes “ more or 
less revolute’? *. ‘This is certainly a transition form. The 
distinctive characteristics of Pedicellinopsis are the arborescent 
form (which is by no means comparable with the mere 
ordinary variations in habit amongst the calcareous Cheilo- 
stomata), the specialized muscular structure, and (primarily) 
the highly developed periderm. In the localization of the 
muscular power this genus agrees with Pedicellina gracilis and 
with the remarkable Arctic genus Barentsia, mihi. In the 
possession of the first of the characters named it stands alone 
amongst the tribe; the last it shares (though with an im- 
portant difference) with Urnatella, Leidy, a very interesting 
and beautiful form from the American fresh waters. 
Pedicellinopsis fruticosa, n. sp. (Pl. XIV. figs. 3-3.) 
Zoarium erect, consisting of a number of stout chitinous 
stems rising from a mat of tubular root-fibres, and sending 
off branches sparingly and irregularly, the whole forming a 
bushy shrub-like growth. olypides borne on the summit of 
tall chitinous tubes, obliquely truncate at the top, and pro- 
duced at the upper side into a sharp spinous projection, 
terminating below in large turbinate expansions with an 
opaque-white core and chitinous envelope, annulated through- 
out, which are attached to the stem by the inner side towards 
the base, and are thickly crowded upon it; body of the poly- 
pide cup-shaped, whitish, ventricose on one side and almost 
straight on the other ; tentacles (probably) about twenty ; the 
tubes traversed by four double lines, the spaces between them 
being occupied by a row of minute disks, which project from 
the surface. Height of the zoarium about one inch. 
Loc. Port Phillip Heads (J. B. Wilson). 
The tubes are densely crowded on the stems, which they 
* See his paper entitled “ Urnatella gracilis, a Freshwater Polyzoan,” 
Journ. Ac. Nat. Sci. Philad. vol. ix. 
