COMPARISONS. 



With columns for Sea-anemone and for Hydroid, answer 

 the following questions: 



(1) Are the animals simple or do they form colonies 

 connected together? 



(2) Can you find traces of bilaterality in the animals? 



(3) Are septa present? Is the digestive cavity simple, 

 or is it subdivided into chambers? 



(4) Is there an in turned oesophagus? 



(5) Are the tentacles hollow or solid? 



Read the accounts of the Hydrozoa (pp. 165 to 169) 

 and of the Scyphozoa (pp. 169 to 174). 



128 



