PLATE 25. 



Fig. i .Orchistoma pileus, mature medusa, female. Gult Stream, Tortugas, 



Florida, July 4, 1906. 



Fig. 2. Orchistoma pileus. Part of the bell-margin. 

 Fig. 3. Orchistoma pileus. One of the ocelli showing the ectodermal doubly 



convex lens and the entodermal pigment. 

 Fig. 4. Orchistoma pileus. One of the lips. 

 Fig. 5. StdiirrjJiscus tetrastaurus. Side view of mature male. Tortugas, 



Florida, August, 1898. 

 Fig. 6. Staurophora mertensii, young medusa. Nahant, Massachusetts, 



May 7, 1897. 

 Figs. 7 and 8. Dipleurosoma collapsa, young stage in the growth of the 



medusa. Tortugas, Florida, and Nassau, Bahamas, July, 1902-03. 



Drawn from life, by the author. 



