ITAR-FISHES. 



109 



may be described as a thick head, cleft into three divisions, 

 and set on a long, slender, flexible stalk. Through a por- 

 tion only of the stalk passes an inflexible shelly support 

 like a bone, but there is left a considerable part which is 

 perfectly soft, flexible, and highly contractile ; and by the 

 motions of this part, the massive head is thrown about in 

 all directions with great vivacity. 



Now let us look at the heads of these strange nodding 

 creatures. The largest sort has a head shaped something 

 like a sugar-loaf, split from the apex to the base into three 

 lobes, which gape widely and close together with most 

 ferocious snappings. These openings and shuttings of 

 the threefold jaws are constantly going on, fitfully and 

 without any regularity or agreement ; and most curious 

 it is to watch them, and to endeavour (though without 

 success) to discover what possible end is accomplished by 

 the procedure. 



If we examine these bodies with high microscopic powers, 

 little light is afforded on the question of their special 

 functions, though they are thus determined to be organic 

 appendages of the Echinus. But new admiration is ex- 

 cited at their elaborate structure and finish. The head 

 consists principally of calcareous substance, which, as well 

 as the supporting column of the stalk, is penetrated with 

 isolated cells throughout. The bases of the three-lobed 

 head are articulated in the most remarkable manner ; and 

 the lobes themselves, which are sometimes attenuated to 

 three slender pins, are cut along their meeting edges into 

 minute teeth, which fit and lock into each other with 

 exquisite precision. The whole body and head are in- 

 vested with a gelatinous flesh, in which are imbedded 



