EXPLANATION OF THE PLATE. 
Figure I. Rejiresents a bird’s-eye view of the 
Siren, or Proteus, in the act of swimming in a circu- 
lar vessel of water. (See p. 33.) The two oval 
marks, on the anterior part of the head, represent the 
eyes, which are of a bluish color, and seem to be 
well described by Dr. Garden, as lurid.” 
Figure II. A magnified representation of one of 
the branchiae, exhibiting, on one side, the beautiful 
feather- like structure of these organs of respiration 
and of swimming. (See p. 13.) 
Figure III. An under view of the Siren, while at 
rest at the bottom of his vessel of water, the branchiae 
being collapsed. — The two oval marks, near the an- 
terior edge of the head, represent the nostrils. (See p. 
17.) — The rictus of the mouth, or lips, is also dis- 
tinctly represented. 
Fi GURE I and Figure HI, represent one of the 
Sirens (Seep. 9.), upon which I made my experi- 
ments and observations, nearly one half the natural 
size. 
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