238 COMPARATIVE ZOOLOGY. 
Fie, 186.—Hydra: 2, with tentacles fully extend- 
ed; 3, creeping; 5, budding. 
the creature feeds and 
creeps. Closely related 
to the Hydra are the 
compound Sertularians, 
often mistaken for del- 
icate sea-weeds. The 
commonest species on 
our Atlantic coast (Dy- 
namend) is of a pale- 
yellow color, and hangs — 
in fringes from sea- 
weeds, shells, and rocks. 
The ordinary Acaleph 
has a soft, gelatinous, 
semi - transparent, bell- 
shaped body, with tubes 
radiating from the cen- 
tral cavity to the circumference, where they are connected 
by a circular canal, 
and with the margin 
fringed with stinging 
tentacles. The radia- 
ting parts are in multi- 
ples of four. Around 
the rim are minute 
colored spots, called 
“eye-specks,’ sup- 
posed to be the earli- 
est indications of the 
organs of sight. In 
fine weather, these 
“sea-blubbers” are 
seen floating on the 
sea, mouth downward, 
moving about by flap- 
SX 
XS 
> 
~~ 
Y 
[AE 
Wy SS ib 
NRE) 
Ay) Ye 
—\ 
Fie. 187.—Sertularia growing on a Shell. 
