138 THE WATER CABINET. 
anterior one is punctured, and runs parallel with the 
margin. The elytra are turned in at the sides, and the 
surface of each is marked with eleven striz or longitudinal 
lines, composed of minute punctures. The terminal seg- 
ment of the abdomen, together with the legs, are of a 
rust-red. 
If we inquire by what means it is enabled to perform 
its elegant performances on the water, and which very 
closely resemble those of a skilful skater on the ice, we 
1H 
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find that its structure is eminently fitted for such peculiar 
movements. In the first place, the antennz are short and 
thick; if they protruded forward to a great length, as in 
Longicornes, they would seriously impede the freedom of 
action, which is the life and joy of this nimble fellow, 
They are clavate, and consist of seven closely-jointed rings, 
each antenna being attached by a slender peduncle to the 
upper and internal edge of a large radical joint furnished 
with an auricle at its outer side, which, like the lid of a 
box, shuts in the antenne when unemployed, and protects 
