202 
Mr. A. Hancock on the Anatomy of the 
EXPLANATION OF PLATES II., IIL., IV. anp V. 
Puate II. 
Fig. 1. Upper portion of Fredericella sultana seen as a transparent object 
very much magnified: a, tentacular disc; 5, tentacles; c', mem- 
brane at base of ditto; c, flomced margin of ditto; d, mouth; 
e, oral valve; f, oesophagus; g, projecting lips of cardiac orifice ; 
h, stomach ; 7, intestine; 7, anus; k, nervous ganglion giving off 
nerves ; J, tentacular sheath doubled upon itself; m, strong ra- 
diating muscles for preventing complete inversion of ditto ; n, de- 
licate radiating muscles in connexion with the orifice of cell; 
o, outer wall of cell; p, mner wall or tunic; q, inverted lips of 
orifice ; r, the point where the same unite to the tentacular sheath, 
immediately below which is the sphincter for closing the cell. 
Fig. 2. Retracted polype of Plwmatella Alimani seen by transmitted light 
and much magnified : a, bundle of tentacles enveloped in mem- 
branous sheath; a’, fentaculan disc; 6, cesophagus ; ¢, project- 
ing lips of eee opening ; d, Susu he e, intestine; f, anus ; 
gg, muscles for retracting the polype; h, large radiating muscles 
for preventing complete mversion of tentacular sheath ; 7, delicate 
radiating muscles in connexion with the orifice of cell; j, outer 
wall of cell; &, immer membrane or tunic; /, verted margin or 
lips of orifice; m, tentacular sheath; , sphincter contraction of 
ditto ; o, bud in second stage of development ; p, tentacular sheath 
of ditto forming; q, retractor muscles in an incipient state. 
Fig. 3. Upper portion of the cell of Plumatella Alimani much enlarged : 
a, bud in first stage of development attached to the mner surface 
of lining membrane of cell. 
Fig. 4. Cell with exserted polype of Fredericella sultana much enlarged 
Fig. 
Fig. 
ye 
1g. 
Fig. 
Fig. 
and seen as a transparent object : a, tentacular dise ; b, oral valve ; 
c, cesophagus; d, stomach; e, intestine; f, the two bundles of 
polype retractors ; g, two fibres of same for rotating tentacular 
dise ; h, egg in connexion with ovary, attaching it to lower end of 
stomach and wall of cell; h’, appendage to the lower end of stomach, 
probably generative ; 7 7, outer wall of cell; jj, immg membrane 
or tunic; k, bud in third stage of development 3 J, tentacles of 
ditto as they at first appear ; m, stomach of do. ; , retractor muscles 
of ditto; o, nucleated cell—the incipient egg im connexion with 
the ovary. 
. Bud in third stage of development more highly magnified: a, ten- 
tacular disc ; , ; esophagus ; c, stomach ; d, mtestine ; e, incipient 
egg in enlarged portion of ovary ; f, wall of cell. 
. Egg and ovary much enlarged of Fredericella sultana: a, egg im- 
bedded in ovary 3 b, wall of cell to which lower end, ¢, of ovary 
is attached ; ec’, upper portion of ovary leading to stomach. 
PuaTe III. 
. Side view of exserted tentacular apparatus much enlarged of Plu- 
matella punctata: a, oesophagus ; 4, oral valve; c, tentacular or 
oral arms ; d, tentacles; e, membrane at base of ditto; f, laminz 
at back of ditto. 
. Enlarged view of under side of tentacular apparatus of Plumatella 
Almanks a, margin of orifice of cell; b, intestine ; c, cesophagus ; 
d, oral valve ; e e, oral arms; f, membrane at base of tentacles. 
. Enlarged view of the upper side of tentacular apparatus of Pluma- 
