130 MAY. 



the antennae placed close together, and also pointing 

 straight upward from the head. This is, doubtless, the 

 attitude in which the animal sits in its burrow, for the 

 tips of the antennae may often be seen just projecting 

 from the sand. When the chosen seat has happened to 

 be so close to the glass side of the tank as to bring the 

 antennae within the range of a pocket lens, I have 

 minutely investigated these organs, without disturbing 

 the old warrior in his meditation. I immediately saw, 

 on each occasion, that a strong current of water was 

 continuously pouring up from the points of the ap- 

 proximate antennae. Tracing this to its origin, it be- 

 came evident that it was produced by the rapid vibra- 

 tion of the foot-jaws, drawing in the surrounding water, 

 and pouring it off upwards between the united antennce, 

 as through a long tube. Then, on examining these 

 organs, I perceived that the form and arrangement of 

 their bristles did indeed constitute each antenna a semi- 

 tube, so that when the pair were brought face to face 

 the tube was complete. It is difficult to make this 

 arrangement intelligible by mere words ; but I may say 

 that if either of the antennae were broken off in the 

 middle and viewed vertically, the bristles would be seen 

 to project from each side of the inner face, in a curved 

 form, each making about a fourth of a circle, so that 

 the two corresponding bristles enclose, with the body of 



