564 PEDICELLINID.E. 



and cardinal character are others which^ though secon- 

 dary, are of great interest and systematic value. The 

 tentacles are not attached to a retractile portion of the 

 cell : there is no invagination of the anterior region, and 

 consequently no tentacular sheath. The arms originate 

 from the upper margin of the cup-like body, and are 

 bilaterally disposed ; they are not withdrawn into the 

 cavity of the cell, but merely rolled up, when at rest, and 

 in this condition are partially within the vestibule which 

 occupies the upper portion of the body. The integument 

 of the body (equivalent to the zooecium) is comparatively 

 soft, and is never strengthened by calcareous material ; 

 it immediately incloses the alimentary canal ; and there 

 is therefore no perivisceral space, like that by which the 

 polypide is surrounded in the ordinary Polyzoa. The 

 polypide of the Entojjrocta is incapable of the lively 

 movements which are so characteristic of the latter : 

 it is fixed in its cell; and the system of muscles concerned 

 in the acts of protrusion and retraction, which attains so 

 high a development in other sections of the class, is 

 wanting. The Pedicellinida are all furnished with a 

 contractile stem, on the free extremity of which the 

 body is placed; and this peculiarity distinguishes them 

 in a very marked way from the rest of the Polyzoa. 



Genus PEDICELLINA, Sars. 



Der. From pes, a foot. 



Pedicellina, Sars, Beskrirelser &;c. (183.'>) : Johnston : Van Betieden : 



Nitsche : Smitt : &c. 

 Hydra (part.), Bosp : Blain\ille : &<;. 

 Chino.morpha, Van Beneden (1844). 



Generic Character. — Polvpides pedunculate, distri- 



