BRYOZOA, WITH DESCRIPTIONS OF NEW SPECIES. 393 
sembling Oercarie. I have detected similar bodies in Bower- 
bankia with large rounded heads and long tails ; they were very 
numerous, and moved rapidly about in the interior of the cell in 
the manner of tadpoles, that is, with a lateral undulating motion, 
and are assuredly Spermatozoa. A testis may then be expected 
to exist in the freshwater Bryozoa coextensively developed with 
the ovary, and from analogy to be associated with it. It is not 
unlikely therefore that these additional filaments from the sto- 
mach, may be really the male organ. 
Hach polype does not appear to produce more than two or 
three eggs; in Plumatella frequently only one. In P. Allmani 
they, Pl. IV., fig. 5 f are considerably depressed, of an oval form, 
sometimes very long with the sides almost parallel; they are very 
large, being sometimes almost as wide as the diameter of the cell, 
within which they are placed lengthwise; the margins are reti- 
culated, yellow, pellucid, thin, and sharp, forming a well-defined 
rim about the central portion, which is opake and black; the 
covering is smooth, tough, and membranous. In /redericella, the 
ego is broader and more regularly oval, ofa brownish colour with 
the margin narrow, plain and of a paler hue. The egg, Pl. V., 
fig. 7 ¢, of Paludicella, if egg it be, differs considerably from the 
above. It is of an irregular oval shape, about half as wide as the 
cell, colourless and pellucid; the surface is marked with a few 
indistinct, irregular, nucleated cells; one larger and much more 
conspicuous than the rest, with a distinct round nucleus in the 
centre, is always to be seen on one side. The circumference of the 
egg exhibits a double margin indicating an enveloping shield. 
The great size of the egg forbids the possibility of its escape 
without the destruction of the polype.* In Plumatella, the ova 
* The polype of the marine species must also perish on the escape of the 
gemmule. On examining some specimens of Bowerbankia in August, almost 
every cell was found to contain a large, round, opake, bright yellow corpuscle. 
These corpuscles were, for the most part, in the lower portion of the cells ; some 
however were half-way up, and others not far from the top: those lowest down 
were the smallest, and as they approached the top they increased in size until 
their diameter was nearly equal to that of the cell. As long as the corpuscle 
remained near the lower extremity of the cell, the polype was alive and active ; 
but was invariably dead when it had advanced far upwards. At first the 
corpuscle does not appear to have any envelope, but as it increases in size 
a distinct margin makes its appearance, which afterwards becoming wider and 
perfectly transparent, the corpuscle can be seen rotating within, by the aid of 
