1818.] OF THE UNITED STATES. 381 



Length, male one quarter, female three twentieths of 

 an inch. 



Inhabits coast of Georgia. 



Cabinet of the Academy. 



This active little animal is one of the many inhabi- 

 tants of small pools of water left by the recess of the tide 

 on the coast of Georgia and Florida, and it is probable, 

 considering the vast range of animals on this eastern part 

 of North America, that it occurs much farther north, es- 

 pecially as it is found in considerable numbers in the lo- 

 calities I have assigned to it. In those shallow pools its 

 presence may be ascertained by the numerous and irre- 

 gular tunnels which it forms in the sand, like miniature 

 representations of those of the mole, only less rectilinear. 

 These little tubular edifices are formed by the animal 

 when in pursuit of a recluse prey, and are occasionally 

 interrupted by his ascent towards the surface of the wa- 

 ter. In these excursions his motion is extremely rapid, 

 and appearing but for a moment, he is readily mistaken 

 for a Dytiscus or Hydrophilus, which have a similar habit 

 of occasionally visiting the surface of the water; but for 

 the purpose of respiration. I was at first deceived by this 

 similarity of movement, until by more attentive observa- 

 tion, induced by the rapidity with w^hich it penetrated the 

 compact sand and by its not remaining at the surface of 

 the water a sufficient time to inhale a supply of air, or to 

 collect a globule of it for gradual consumption, it was 

 evident that it was an animal of perfectly distinct habits 

 and organization from those of simple stigmata. 



When placed in a vessel of water, it was observable 

 that the oval appendices attached near the inner base of 

 the anterior pairs of feet, assist in the process of respiration 

 Vol. L I \ 



