388 MR. HANCOCK ON THE ANATOMY OF THE FRESHWATER 
similar in all the Bryozoa, only those at the inferior extremity 
of the stomach in the marine species appear deficient in the 
freshwater forms. They all have, however, one or more appen- 
dages to this part, but these we shall afterwards see are most 
probably connected with the reproductive system. The parietal 
and sphincter muscles are common to both Paludicella and the 
marine forms. On the whole, then, in the muscular system as 
well as in the digestive apparatus, Paludicella shows a close re- 
lationship to Bowerbankia and its congeners ; and is, in fact, 
an intermediate link between them and the other freshwater 
Lryozoa. Hven the minute structure of the muscles themselves 
would seem to confirm this. In all, they are composed of trans- 
parent, linear fibres separated from each other and apparently 
homogeneous. When broken they become irregularly nodulous; 
but I have not succeeded in detecting transverse strie observed. 
by Professor Allman, probably from having used insufficient mag- 
nifying powers. The small knot-like swelling, so remarkable in 
the centre of the fibre of the marine species, is not to be found in 
either Plumatella or Fredericella; in Paludicella, however, I 
have observed it in the parietal, but in no other muscles. 
Reproductive System.—In the freshwater, as in the marine 
Bryozoa, there are two methods of reproduction,—one by buds, 
the other by eggs. The buds always germinate from the same 
part of the cell, hence the definite form of the polypidom. In 
Fredericella the germ is found in connection with the inner sur- 
face of the tunic, not far below the orifice of the cell on its lower 
side. As the bud enlarges the wall bulges, showing externally 
the appearance of a new shoot. At first the bud, Pl. III. fig. 3a, 
is small and oval, and is attached for nearly its whole length; it, 
fig. 2 0, soon becomes irregular in form, with the upper portion 
broad and somowhat bifid, the lower extremity prolonged: the 
upper portion then gradually exhibits a circle of short rudimen- 
tary tentacles. fig. 47,; and the lower end is seen to be divided 
longitudinally into esophagus and intestine, fig. 5 6, d, continu- 
ous at their lower extremities, which still elongating, form the 
stomach, figs. 4m & 5c. ‘To this is seen an appended filament 
binding it below to the wall of the cell. Imbedded in this 
