162 On Grantia ciliata, var. spinispiculum, Cr¢r. 
become disintegrated ; the liquor poured off and the residuum 
in the watch-glass washed twice only with pure water, most 
carefully draining throughout, lest the minute spicules be 
carried away by the edulcoration ; then the last drop containing 
the spicules should be transferred to a glass slide and drained 
again, but not to perfect dryness ; now add one or two drops 
ot glycerine, and secure the whole under a large glass cover, 
finally adding a little balsam at the cardinal points to keep it 
from slipping. ‘This process has the advantage of preserving 
all the spicules, small and great, and, from their not having 
been reduced to absolute dryness, of preventing that crystal- 
lization of the remaining potash around them which otherwise 
would inevitably obscure their forms, while it yields a prepa- 
ration which can be recurred to for deliberate examination as 
long as it may be required. 
P.S.—A delicate spiniferous spicule, to which attention has 
not hitherto been directed, exists all over the surface of Leuco- 
gypsia Gosset, often fringing the mouth too in the manner of a 
peristome. It is fusiform, slightly curved, and spined proxi- 
mally, chiefly over one side only, while the free extremity is 
armed, bayonet-like, with a short, delicate, smooth, slightly 
curved spur. 
EXPLANATION OF PLATE VIII. 
Note.—The representations in this Plate must (with the exception of 
fig. 1, which is of the natural size) be regarded as diagrams drawn to 
scale, that the reader may be able to realize as far as possible the relative 
proportions of the different parts of which fig. 1 is composed. Thus fig. 2 
has been drawn to the scale of about 1-96th to 1-180U0th inch, and even 
here the scale is not sufficiently large to show the spines on the spicules ; 
so these, viz. 3, 4, and 5, have been drawn to the scale of 1-24th to 
1-6000th inch; while for perspicuity also figs. 6 and 7 are magnified to 
double the size of the same parts in fig. 2, 
Fig.1. Grantia ciliata, var. spinispiculum, Crtr., single and double. 
Natural size. 
Fig. 2. The same. aaa, body; 6, peristome and collar; c, stem and 
root; dd, cones on the surface, direct view; ee, the same, 
lateral view, showing their connexion with ff, the radial cham- 
bers; g, peristome; A, collar; 2, stem ; k, root; ///, dotted line 
showing the form of the internal cavity or cloaca; m, openings 
of the radialchambers into the cloaca ; », projection of the fourth 
ray of the quadriradiates of the cloaca into that cavity. 
Fig. 8. The same. Spined spicule of the cone with curved free extremity, 
about 1-13th inch long. a, inflated, smooth, or proximal end ; 
b, curved, serrated or distal end; c, shortest form seen, about 
1-461st of aninch. Teeth directed outwards. 
Fig. 4. The same. Spined spicule of the cone and root, with a straight 
free extremity, about 1-28rd inch long. a, inflated, smooth, or 
proximal end; 4, straight, toothed, or distal end; c, shortest 
