112 



Of the eiglit tentacula of this AmKlide, one pair, that towards the 

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

 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, svvinging 

 itself frora side to side, and moving its tentacula about. If anything 

 is discovered suitabie 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. 



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



Obs. Genus propter tentaculorum branchiferorum dispositionem 

 a Sahelld, Cuv., sejungendum, 



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

 ribus nigro confertim interrupte annulatis. 



Hab. in saxis corallinis apud Black River. 



The cilia of the tentacula 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 ręst, 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 ofthe tube, turns the disc down with very deliberate mo- 

 tion tovvards the adjacent part of the stone, and apparently exa~ 

 minės the surface vvith minute attention ; the tentacula at this time 

 being constantly nioved about so as to ensure the entrapping of 

 any animal that raay ręst within their reach. 



