112 



Of the eight tentacula of this Annelide, one pair, that towards the 

 ventral aspect, is short, and the opposite pair is long, being fully 

 equal in length to the entire body : the intermediate pairs are inter- 

 mediate also in length. When undisturbed, the animal projects 

 from its tube or shell as far as the fifth or sixth segment, swinging 

 itself from side to side, and moving its tentacida about. If anything 

 is discovered suitable for food, the extremity of one or more of the 

 tentacula is rolled around it, and by this means the substance is con- 

 veyed to the mouth. The tentacula are numerously ringed, and 

 have in their interior a tube in which oval globules are distinctly 

 seen moving to and fro, as the motions of the tentacula affect a few 

 contiguous rings. 



PiRATESA. 



Os tentaculis seu branchiis numerosis, longe ciliatis, subulatis, 

 simplici serie dispositis, cinctum. 



Testa cylindrica, calcarea, erecta, e saxo parum prominente. 



Obs. Genus propter tentaculorum branchiferorum dlspositionem 

 a Sabelld, Cuv., sejungendum, 



PiRATESA NIGRO-ANNULATA. Pir. brunnea, tentaculis pallidio- 

 ribus nigra confertim interrupte annulatis. 



Hab. in saxis corallinis apud Black River. 



The cilia of the tentacida arise in a single row along each edge of 

 the upper surface, and turn in upon any substance that is seized so 

 as to embrace it tightly : when at rest, they are doubled up into 

 little coils or knots, and are only expanded when the animal is 

 searching for food. When engaged in this operation it elevates 

 itself out of the tube, turns the disc down with very deliberate mo- 

 tion towards the adjacent part of the stone, and apparently exa- 

 mines the surface with minute attention ; the tentacula at this time 

 being constantly moved about so as to ensure the entrapping of 

 any animal that may rest within their reach. 



