WHEEZE-BEARERS 



283 



after they are discharged; the minute green oval bodies 

 that you see sticking to the side of this specimen are not, 

 however, eggs, but parasitic animalcules (Colacium vesi- 

 culosum), which very frequently infest this species, adher- 

 ing to various points of the shell, and even to the sword- 

 fins. 



What I have now to submit for your examination is 

 one of the rarest species of the class, and certainly not the 

 least singular in its form. It is the Tripod Wheel-bearer 

 (Actinurus Neptunius). When fully 

 extended, its length exceeds that of 

 almost every other species, for it 

 reaches about one-twentieth of an 

 inch, but its extreme thread-like 

 slenderness precludes the unassisted 

 eye from taking cognizance of it, as 

 its thickness, even when greatest, is 

 not more than one six-hundredth of 

 an inch. 



From this excessive length and 

 tenuity, the appearance of the crea- 

 ture 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 terminate in an oval probos- 

 cis, which having a sort of finger at its extremity, and two 

 eyes, with an antennal tube projecting obliquely backward, 

 presents, when viewed laterally, a strong resemblance to the 

 head of a rabbit, the antenna representing the ears. In 

 front, and just below this head-like proboscis, is a double 

 swelling, containing the rotatory organs, which are small and 

 seldom unfolded. The eyes are deep black; probably, as in 



TRIPOD WHEEL-BEARES. 



