4 Pol. 
POLYZOA. 
homologous with the head kidneys of Trochosphere larvae. No her¬ 
maphrodite individuals were discovered in any species ’ of Loxosoma or 
Peclicellina. 
Urnatella gracilis (Leidy). Some specimens of this species have been 
described, (7) p. 282 et seq., nearly all of which consisted of two stems of 
unequal length and devoid of terminal polyps. In March the stems had 
all developed polyps at the distal end. Most were terminated by a single 
polyp, but a few had also a smaller one on a cylindrical joint springing 
from the ante-penultimate joint of the stem. If portions of the stem 
are destroyed, the remaining joints are capable of reproducing the polyps. 
Branches usually spring from the last one or two joints, newly produced 
from that which immediately supports the terminal polyp. Heads may 
start laterally from old or mature joints. Thus the latter appear to serve 
as the “ statoblasts ” of other fresh-water Polyzoa , but ordinarily they do 
not become isolated from one another. 
Lankester (6) describes in detail the structure of Paludicella ehren- 
bergii. The terms “ectocyst,” “ endocyst,” and “endosarc ” are rejected, and 
after a brief account of the different groups of the Polyzoa , the author 
passes on to the consideration of their genealogical relationship. 
Fkesh-watek Polyzoa. 
Of Plumatella hyalina and lophoposidea, Klafka (5) remarks that the 
first is allied to P. vesicularis [= Hyalinella vesicularis , Jullien (see 
below)] by the transparency of its tubules, which arise radially from a 
centre and branch dichotomously at some distance from it. The second 
species apparently resembles Lophopus , but the gelatinous investment of 
the mass is an ectoblast membrane, while the organization of the cells 
and polypides is that of Plumatella. Fredericella sultana , with two 
varieties, are common in Bohemian waters. Alcyonella fungosa has 
two kinds of statoblasts. Of Gristatella mucedo the author remarks that 
for a long time he was unable to convince himself of the locomotive 
powers of the species. 
Jullien (4) recognizes two sub-classes, in the former of which there are 
two tribes : 
Bryozoa Lophoda. 
I.— B. lophopoda-caduca. 
(a) Family Pedicellinidce. 
(/3) ,, Loxosomidce. 
II.— B. lophopoda-perstita. 
(a) Family Plumatellidce. 
(IB) ,, Lophopusidce. 
(y) ,, Rhabdopleuridce. 
B. Infundibulata. 
(a) Family Paluclicellidce. 
(13) ,, Hislopidce. 
A new genus, Hyalinella , is instituted for Plumatella vesicularis , 
Leidy, p. 133. 
