CEABS AND SHKIMPS. 199 



question. The Crab always carries them erect and 

 elevated ; and is incessantly striking the water with 

 them, with a very peculiar 

 jerking action, now and then 

 vibrating, and, as it has been 

 called, " twiddling " them. 

 These antennje, therefore, ap- 

 pear to be always on the 

 watch: — let the animal be at 

 rest, let it be feeding, no mat- '=^'' °' ''^^^' ^"'™ '=™""'- 

 ter, the superior atennse are ever elevated and on con- 

 stant guard. 



The lengthened and delicate setse with which they 

 are furnished, are, moreover, peculiarly adapted to re- 

 ceive and convey the most minute vibratory sensations 

 from the medium in which they are suspended ; and, 

 on the whole, it seems to be satisfactorily settled by 

 Mr. Spence Bate (to whose excellent memoir* I am in- 

 debted for these explanatory details) that the inner an- 

 tennas are real ewrs. 



Having thus taken our Crab by the ears, we will 

 endeavour next to tweak his nose. But stay, we must 

 find it first. We turn our horny gentleman up, and in 

 his flat ancient face we certainly discern little sign of a 

 nasal organ. Our friend Mr. Bate must assist us 

 again. He will tell us to look at the outer or lower 

 antennae. "We will look accordingly, magnifier in 

 hand, while he makes it clear to us that these are a 

 pair of noses. 



Each of these organs is formed of a stem consisting 

 in general of five joints, and a filament of many min- 

 ute joints. In the Prawn and the Lobster all the five 

 * Annala of Nat. Hist, for July, 1855. 



