THE HYDROUS PICE US. 
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not maintain itself horizontally at the surface of the water, but 
it pokes out its head above water mark, and folds its antennae, 
the metamorphosis OF Hydrophilus piceus. 
the club-shaped ends of which are partly hollowed out ; and thus 
carries downwards a small bubble of air, which is pressed against 
the sides of the thorax and of the abdomen, and which then comes 
