BRYOZOA, WITH DESCRIPTIONS OF NEW SPECIES. 389 
filament there is a large, distinct globule with nucleus and nu- 
cleolus : this we shall afterwards learn is the incipient ovum, 
figs 40 & 5 e, lying in the ovary. The polype-retractors, figs. 
2q&4n, now make their appearance, passing from the tenta- 
cular base to the side of the cell formed apparently out of the 
lower portion of the original attachment of the bud ; the upper 
portion of this attachment dilating, becomes the tentacular sheath, 
fig. 2 p, into which the tentacles are gradually insinuated as they 
are developed. The polype being now, as it were, sketched out 
within the cell of the parent, its own chamber rapidly forms, and 
in the course of a day or two, the muscles in connexion with the 
orifice being added, the fresh-born member of the community 
bursts from the extremity of its cell, and is ready to take upon 
itself the work of its own maintenance. 
The development of the bud in Plwmatella differs in no re- 
spect from that of Fredericella ; and in Paludicella there is no 
very important deviation, except at the commencement of the 
process. In this the first apparent step in the growth of a new 
polype, is the preparation of a distinct cell for its reception. If 
the top of the last-formed cell be carefully examined, even before 
its tenant is fully grown, the lining membrane may be seen ter- 
minating in a blind sac, Pl. V. fig. 4 0’, a little below the extre- 
mity. Within this extremity will also be observed a membranous 
sac, 7; at first the base of this sac is moulded on the convex 
blind termination of the lining of the old cell. The convexity 
however soon flattens, and the sac rapidly increases in size, the 
external horny covering becoming, at the same time, elongated 
and attenuated. After awhile, an oval, somewhat opake body, 
the new bud, fig. 5 m, germinates from the inner surface of the 
- lining membrane, 7. This body is attached by its side to the 
front wall of the cell, and resembles the young bud in Prederi- 
cella. A long and very delicate membranous sac, fig. 6 d, after- 
wards the tentacular sheath, is now observed to be forming in 
contact with and above the oval bud; whilst from the lower 
extremity, filaments, e, are seen to be produced which form the 
polype-retractors. From the upper end of the bud, the tentacles, 
fig. 4d, soon make their appearance within the lower part of 
