CTENOPHORA. 



249 



sides, and re-descend by tvvo much deeper canals ; the Beroes have 

 no heart. Beroe ovata is a beautiful species, seldom exceeding two 

 inches and a half in length and one and a half in its larger trans- 

 verse diameter; it is described by Browne, in his "Jamaica," as "of 



Fig. 102. — Beroe Forskalii (Edwards). 



an oval form, obtusely octangular, hollow, open at the larger 

 extremity, transparent, and of a firm gelatinous consistence ; it 

 contracts and widens with great facility, but is always open and 

 expanded when it swims or moves. The longitudinal radii are 

 strongest in the crown or smallest extremity, where they rise from a 



