802 THE AMERICAN NATURALIST. [VOL. XXXIIL 
larger ones may contain as many 
as two or three hundred individuals. 
In a figure it is not feasible to rep- 
resent more than a third of those 
found in a dense colony. 
The colony includes two, and 
only two, kinds of individuals, the 
1.— Colony of Legere ferek o. nutritive and the reproductive. 
dork shell of a livi 
which ia aN on a a aara: ae protective spiral zodids found 
f eel 
blade of eelgrass. Natural size. 
Lae y 
= 1h) RAS 
‘ff 9 | N NN 
nA 
Y 
TT 
r AN 
SS 
Saher 
SL ee 
Fic. 2.— Part oi magnified six diameters. (1) 
nu ce Pres Pipe fully nian ; (2) same 
slightly contracted; (3) same fully contracted ; be Act 
roducti 
rep: 
productive hydranth, slightly contracted ; eg fi pated 
ydrorhiza; sø., spines. 
in Hydractinia are not present. 
A small part of a colony, 
enlarged six diameters, is 
represented in Fig. 2. 
The hydranths or indi- 
viduals are sessile, arising 
directly from the compli- 
cated system of tubes, 
the hydrorhiza, which 
closely invest the surface 
of the snail shell. These 
tubes (Figs. 2 and 3) 
form a network lying in 
a general way in one 
plane. From this net- 
work arise the hydranths 
and also a few small 
spines (sp., Figs. 2 and 
3), which seem to be 
homologous with those 
found in such forms as 
Hydractinia and Podo- 
coryne. The tubes dif- 
fer from those of these 
two genera, however, in 
not having the continu- 
ous layer of flesh (the 
cœnosarc) which covers 
the superficial surface of 
