108 ANALOGOUS TYPES. 
may not be easily traced. But the common 
names used by the fishermen often indicate these 
resemblances, — as, for instance, Sea-Vulture, 
Sea-Eagle, Cat-Fish, Flying-Fish, Sea-Porcupine, 
Sea-Cow, Sea-Horse, and the like. 
In the branch of Mollusks, also, the same 
superficial analogies are found. In the lowest 
class of this division of the Animal Kingdom 
there is a group so similar to the Polyps, that, 
until recently, they have been associated with 
them,—the Bryozoa. They are very small ani- 
mals, truly allied to the Clams by the plan of 
their structure, but resembling the Polyps on 
account of a radiating wreath of feelers around 
the upper part of their body: yet, when exam- 
ined closely, this wreath is found to be incom- 
plete; it does not form a circle, but leaves an 
open space between the two ends, where they 
approach each other, so that it has a horseshoe 
outline, and partakes of the bilateral symmetry 
characteristic of its type and on which its own 
structure is based. These series have not yet 
been very carefully traced, and young natural- 
ists should turn their attention to them, and be 
prepared to draw the nicest distinction between 
analogies and true affinities among animals. 
