MOSS-ANIMALS. 
421 
paratively conspicuous; but we might have chosen any other of the many beautiful 
but less conspicuous forms. On any sea-coast a harvest of them can be gathered 
in a few days. Certain species are almost always to be found on nearly every 
leafy seaweed, and where the bottom of the sea is favourable, stones and the 
shells of molluscs, both full and empty, are covered with stocks of Bryozoa, often 
only discoverable by means of careful examination with a magnifying glass. 
Owing; to the 
hardening; and 
frequent calcifica¬ 
tion of the greater 
part of the body- 
wall to form the 
cell into which 
the anterior part 
that always re¬ 
mains soft can be 
withdrawn, these 
animals are often 
found as fossils. 
The marvellous 
variety of forms 
presented by these 
delicate little 
stocks is in each 
case determined 
by the particular 
manner of bud¬ 
ding. The first 
animal which, by 
budding, gives rise 
to the stock is 
produced from an 
eg’g;, and begins to 
bud as soon as it has become attached. In each family or species the buds appear 
at special points, and assume definite positions with regard to the parent individual. 
The smallest variation in this respect causes the profoundest changes in the forms 
of the stocks produced. Their classification is determined principally by the 
structure of the mouth and of the tentacle crown, as may best be gathered from a 
few examples. We take first the subclass Ectoprocta. 
order Most of the fresh -water moss-animals belong to the order 
Phyiactoisemata. Phylactolfemata, so-called because the mouth is provided with a 
tongue-shaped lid. The crown of tentacles, which is also a gill, is horseshoe¬ 
shaped, and the whole surrounded at its base by an integument forming a kind of 
calyx or cup. The chambers or cells are either quite soft or else horny, and are 
thus not found in a fossil condition. Later on in this volume is described a 
colony of sea-anemones which, instead of being fixed, as are most stocks, are 
lace-coral, OR Neptune’s sleeve, Retejpora cellulosa (nat. size). 
