28 CCELENTERATA AND 



A. III. 



Mabdla r/racilis. Larva not observed. 

 Melicerlum campanula. Larva like the adult. 



B. I, a. 



Obelia diapJiana. Larva like adult. 



Clytia bicopltora. Larva in youngest form with two 

 tentacles opposite each other and eight otocysts. 



Oceania languida. Larva in youngest form with two 

 opposite tentacles, four otocysts. Proboscis small, incon- 

 spicuous. 



EucJteilota ventricularis. Larva like adult. 



B. I, b. 



Tima Bairdii. Larva like adult. Tentacles short, 

 numerous. Proboscis small. Otocysts like adult. 

 Eiilima gracilis. Larva not observed. 



JB. II. 



Zygodactyld'-Grcenlandica. Larva in youngest form 

 found with four tubes, four tentacles. Numerous otocysts. 

 Next oldest larva has four complete tubes and four addi- 

 tional tubes extending half way from junction of probos- 



\ cis and bell margin. 



Order I. Hydroida (attached). 



Many of the jelly-fishes originate as buds from an at- 

 tached zoophyte known as a hydroid. To become familiar 

 with the different forms of the young of the Hydrozoa, it 

 is necessary to be able to identify these animals. 



The fixed hydroids are algae-like organisms, simple or 

 branching, with soft or hard axis. They are solitary or 

 social, and give ri^e to medusae by budding or by proc- 

 esses resembling fission. 



