402 MR. HANCOCK ON THE ANATOMY OF THE FRESHWATER 
but, on close examination, are found to be composed of many, and 
rarely to number more than six or eight cells in each. The 
commencement of each polypidom has the black envelope of the 
originating egg adherent. 
Two or three specimens of a more branched form of carinated 
Plumatelia, were taken in Bromley Lough, which may probably 
prove a distinct species ; more individuals, however, are necessary 
before it can be characterized. 
Paludicella procumbens. Pl. VI. figs. 1 & 2, and Pl. V. 
Polypidom membranous, subhorny, pellucid, smooth and glossy, 
ofa brownish horn-colour, much and irregularly branched, forming 
large patches on the underside of stones, for the most part 
adhering, with rather numerous, short, free, almost simple 
branches ; the branches composed of a single series of narrow 
cells arranged longitudinally, contracting towards the base and 
widening upwards ; aperture lateral, near to the upper extremity 
of the cell, forming a rather long and somewhat constricted tube 
inclining upwards ; margin entire, surmounted by a widish, deli- 
cate, hyaline, membranous cup. ‘Tentacles sixteen in number, 
arranged in a complete circle, and when spread out forming a 
very exact inverted cone. | 
This, the second species of the genus, resembles very closely 
P. articulata of Allman, but that form appears to have about 
twenty-six tentacles, and is likewise more densely and luxuriantly 
branched ; the cells, too, are larger and of a different colour. 
The P. procumbens occurred in both Bromley and Crag Loughs, 
but most abundantly in the latter, where it spreads over the 
under surface of stones in patches of 5 or 6 inches diameter. 
EXPLANATION OF PLATES IIL, IV., V., axp VI. 
Puate III. 
Fig. 1.—Upper portion of Fredericella sultana seen as a transparent object 
very much magnified: a, tentacular disc; 6, tentacles; c/, mem- 
brane at base of ditto; c, flounced margin of ditto; d, mouth; 
e, oral valve; f, esophagus ; g, projecting lips of cardiac orifice ; 
h, stomach ; 2, intestine; 7, anus; 4, nervous ganglion giving off 
