SYSTEMATIC 

 ARRANGEMENT OF ACALEPH^. 



CLASS III. 

 ACALEPH^E. 



GELATINOUS animals, swimming freely. Stomach included in 

 the parenchyme of the body, without an abdominal cavity ; canals 

 arising from the stomach, filled with water. Ovaries and testes in 

 one and the same individual or the sexes distinct without organs 

 of copulation. Vestiges of a nervous system not always distinct. 

 Arrangement of parts usually quaternarian. 



ORDER I. SiphonopJiorce. 



[Swimming Polyps without tentacles round the mouth, attached 

 to a common stem of variable length, and moving freely by means 

 of special swimming apparatus, with prehensile filaments, feelers, 

 and protective covers or bracts, or some only of these organs, 

 attached mediately or immediately to the same common stem.] 



This first order includes the A caUphes hydrostatiques of CUVIER 

 and a part of his Acalephes simples. 



Family I. Velellidce or Chondrophorce. Common body, sup- 

 ported by a cartilaginous 1 lamina, which is cellular internally. 



The part of the body which faces upward is supported by a 

 disc, which in Porpita is even in some degree calcareous, and con- 



f 1 The disc contains horny substance, not cartilage, according to LEUCKART.] 



