PLATE i. 



Fig. I. PaehycorJyle degeneratus, male. Nassau Harbor, Bahama Islands, 

 July 19, 1903. 



Fig. 2. Budding hydranth of Pennaria tiarella with female medusa-bud 

 still attached. Agassiz Laboratory, Newport, Rhode Island, 

 July 5, 1895. Found attached to eel grass in shallow water. 



Fig. 3. A recently liberated male medusa of Pennaria tiarella. Agassiz 

 Laboratory, Newport, Rhode Island, July, 1895. 



Fig. 4. Hydroid stock of Pennaria tiarella, natural size. Agassiz Labora- 

 tory, Newport, Rhode Island, July, 1895. 



Fig. 5. Pennaria tiarella. From the coral reef at Tortugas, Florida, May 7, 

 1905. 



fig. 6. Steenstrupia vtrgulata. From a drawing made from life by Dr. 

 Alexander Agassiz at Nahant, Massachusetts, August 21, 1862. 



Fig. 7. Steenstrupia rubra, male. Oregon Inlet, Pamlico Sound, North 

 Carolina, November 12, 1904. 



Fig. 8. HyhoeoJon forbesii. Tortugas, Florida, May 25, 1905. 



Fig. 6, from a drawing by Dr. Alexander Agassiz 

 Figs, i to 5, 7, 8, from life, by the author. 



