PLATE 3. 



Fig. I. Dicodonium Jefferson:. Tortugas, Florida, June 15, 1897. 



Fig. 2. Sarsia rnirabilis, young medusa. Nahant, Massachusetts, March 



26, 1897. 

 Fig. 3. Hybocodon prolijer. t\ primary; t", secondary tentacle beginning to 



develop; m, young medusa-buds. Agassiz Laboratory, Newport, 



Rhode Island, September 17, 1895. 

 Fig. 4. Sarsia mirabilis, mature male. Nahant, Massachusetts, May 7, 



1897. 

 Fig. 5. Hydroid of Sarsia mirabilis with ripe male medusa-bud attached to 



the hydranth. Swallows Cave, Nahant, Massachusetts, May 8, 



1897. 



Drawn from life, by the author. 



