Sto Marvels of 
Photo by] LW. West. 
SNAKE’S-HEAD CORALLINE. 
The creeping stem supports curved branches, each end- 
ing in a single cell, which appear like the foreparts of 
writhing snakes. 
Photo by) [Flatters, Longsight, ; 
FREDERICELLA. 
An example of the fresh-water relatives of the Sea Mats. 
the Universe 
in the species known as the Bird’s-head Coralline. 
The colony forms flat branches arranged in spiral 
tufts an inch or two high, growing upon rocks 
and shells. The “ bird’s-heads”’ are attached by 
short stalks to the sides of ordinary cells. They 
sway backwards and forwards on these stalks, 
snapping their “jaws.” Experiments have shown 
that these jaws can take firm hold of hairs, worms, 
small crustaceans and other small animals held 
near them, but whether they are engaged in 
catching prey remains to be proved. 
In other species these modified zocecia have 
undergone further degradation, the snapping jaw 
having been reduced in thickness and lengthened 
until it resembles a bristle, when it is known as a 
vibraculum. This lashes the water, and sets up a 
current which is supposed to direct food particles 
to the tentacles. In the so-called Snake’s- 
head Coralline each zocecium terminates a long 
branch from a creeping main stem, and when the 
tentacles are withdrawn the curving branch looks 
like the forepart of a writhing snake. 
Our illustrations are all greatly enlarged from 
portions of Sea Mats under the microscope, and 
serve to show some of the many types of form 
and structure to be found in this interesting 
family of animals. The Paper Sea Mat is one 
of those that stand up independent of support 
and are most frequently mistaken for seaweeds. 
The Foliaceous Coralline is a long, slender, 
branching form that runs over shells and red sea- 
weeds, and is one of those that possess numerous 
bristles or vibracula, and is phosphorescent. The 
Fringed Sea-Scurf forms little tufts, about half 
an inch high, and of a pearly white colour, on 
seaweeds and hydroids. The Snowy Dish is an 
example of the section in which the cells are 
composed of lime. They are united to form a 
saucer-shaped disc, about a quarter of an inch 
across. Also of a chalky substance, but with a 
glassy polish, is the beautiful Purple Idmonea, 
whose colonies are about an inch in length. 
The Bugle Coralline is one of the finest of the 
British species. The joints of the forking stems 
are elastic, which enables the three-inch length to 
sway with the movements of the water without 
risk of breaking. The photograph adjoining is 
given as an example of the species that occur 
in fresh water. 
