ACTINOZOA. 231 



lobes. Tentacles two in number, lateral, 

 turned from the mouth. 



Sub-order 2. Eurystomata, 



Family 5. Beroid^. 



Body oval, elongated, without oral lobes. 

 Tentacles absent. 



Here we have slightly modified the definitions 

 of Gregenbaur, at the same time indicating what 

 appears to be the most natural sequence of the 

 several families. The group Callianiridce must 

 for the present be considered as merely provisional. 

 The four other divisions of Ctenophora have been 

 recently elevated by Agassiz to the rank of sub- 

 orders, and the entire number of families increased 

 to ten. This arrangement, however, presents no 

 advantage over the more simple and natural one 

 adopted by Gregenbaur, which, in its turn, must 

 be regarded as an improved modification of the 

 prior classification of Eschscholtz. 



Section IV. 



DISTRIBUTION OP ACTINOZOA. 



I. Relations to Physical Elements. — 2. Bathymetrical Distribution. 

 — 3. Geographical Distribution. 



I Relations to Physical £leiiieiits. — All 



the Actinozoa are marine. 



2. Bathymetrical Distribution. — Upon the 

 whole it may be said that the Alcyonaria are less 

 abundant between tide-marks, and occur in deeper 



Q 4 



