Notes on Medusa of the Western Atlantic. 



'55 



Comparison of morphological characters of Cassiopea xamachana and Polyclonia 



frondosa. 



Cassiopea xamachana. 

 Color: 



Yellowish-brown. 

 Pattern: 



Concentric bands, light and dark. 

 White spots near center. Margin 

 white without spots. 

 Shape of disk: 



Concave above, with raised circular 



band. 

 Appendages of oral arms: 



Yellow digitate appendages. Not 



sensitive. 

 Oral arms: 



Projecting beyond margin of disk. 

 Sense-organs: 



Not less than 13 in adult. 



ZOOLOGICAL LABORATORY, 

 University of Vermont. 



Polyclonia frondosa. 

 Color: 



Olive-brown. 

 Pattern: 



Dark center without spots. No bands. 

 Margin with numerous distinct 

 spots. 

 of disk: 

 Flat. No band. 



Appendages of oral arms: 



White scales guarding oral funnels. 



Irritable and contractile. 

 Oral arms: 



Shorter than diameter of disk. 

 Sense organs: 



12 in recently matured individual. 



