280 



EVEKINGS AT THE MICROSCOPE. 



What I have now to submit for your examination 

 is one of the rarest species of the chiss, and certainly 

 not the least singular in its form. It is the Tripod 

 "Wlieel-bearer {Actinurus Nejptunius). When fully ex- 

 tended, its length exceeds that of almost every other 

 species, for it reaches about one-tAventieth of an inch, 

 but its extreme thread-like slenderness precludes the 

 unassisted eye from taking cognizance of it, as its thick- 

 ness, even when greatest, is not more than one six- 

 hundredth of an inch. 



From this excessive length and tenuity, the appear- 

 ance of tlie creature is very remarkable. It may be 

 likened to a cylindrical tube, out of which protrude a 



great number of draw-tubes from 

 both extremities, principally the 

 posterior one. Those in front ter- 

 minate in an oval proboscis, which 

 having a sort of finger at its ex- 

 trcmity, and two eyes, with an 

 antennal tube projecting oblique- 

 ly backwards, presents, when 

 viewed laterally, a strong resem- 

 blance to the head of a rabbit, the 

 antenna representing the ears. In 

 front, and just below this head- 

 like proboscis, is a double swell- 

 ing, containing the rotatorv or- 

 gans, which are small and seldom 

 The eyes are deep black ; probably, as in 

 the last example, a red of great intensity. When the 

 head is withdrawn, the integument is very clearly seen 

 to be introverted. The body consists of one long cylin- 

 drical tube, which receives three or four short joints to 



TRII'OD WHEEL-BEAKER. 



unfolded. 



